lambda_tmp

from moviepy.editor import VideoFileClip, ImageClip, CompositeVideoClip
import moviepy.video.fx.all as vfx
import os
import mux_python
from mux_python.rest import ApiException
import requests 
import uuid 
from moviepy.editor import *
from moviepy.video.compositing.concatenate import concatenate_videoclips
from time import sleep
import re 
import json 
import gizeh
import tempfile
import os 

def lambda_handler(event, context):
    with tempfile.TemporaryDirectory() as tmpdir:

        VID1 = os.path.join(tmpdir, "loom.mp4")
        VID2 = os.path.join(tmpdir, "loom1.mp4")
    
        PIC1 = os.path.join(tmpdir, "image1.png")
        PIC2 = os.path.join(tmpdir, "image2.png")
        
        MASK_1_PNG = os.path.join(tmpdir, "mask1.png")
        MASK_2_PNG = os.path.join(tmpdir, "mask2.png")
    
        FINAL_VID = os.path.join(tmpdir, "final.mp4")

    def generate_video():
        print('starting to process the video with moviepy')
        # load video 1
        vid1 = VideoFileClip(VID1)#.subclip(0, 4)
        vid1 = vid1.resize(0.6) # 70% of its size

        # load video 2
        vid2 = VideoFileClip(VID2)#.subclip(0, 4)
        vid2 = vid2.resize(height=vid1.h)

        def create_circle(size, name):
            WIDTH, HEIGHT = size# vid1.size
            surface = gizeh.Surface(WIDTH, HEIGHT)

            circle = gizeh.circle(r=min(WIDTH, HEIGHT)//2, fill=(2,2,2), xy=(WIDTH//2, HEIGHT//2))

            circle.draw(surface)

            # save to png
            surface.write_to_png(name)
            
        ''' CREATE MASKS AND ADD IT TO VIDEOS '''
        # generate mask png with correct size
        create_circle(vid1.size, MASK_1_PNG)
        create_circle(vid2.size, MASK_2_PNG)

        ''' FOR FIRST VIDEO '''
        # load mask image
        MASK_1 = ImageClip(MASK_1_PNG, transparent=True,ismask=True)
        MASK_1 = MASK_1.set_duration(vid1.duration) # set duration
        MASK_1 = MASK_1.set_fps(15) # set fps

        # convert mask img to vido clip
        MASK_1 = CompositeVideoClip([MASK_1], bg_color=(0),
                                    size=vid1.size, ismask=True)
        # set mask to video
        vid1.mask = MASK_1 
        vid1 = concatenate_videoclips([vid1], method='compose') # combine with video

        # vid1.preview(audio=False)

        ''' FOR SECOND VIDEO '''
        # load mask image
        MASK_2 = ImageClip(MASK_2_PNG, transparent=True,ismask=True)
        MASK_2 = MASK_2.set_duration(vid2.duration) # set duration
        MASK_2 = MASK_2.set_fps(15) # set fps

        # convert mask img to vido clip
        MASK_2 = CompositeVideoClip([MASK_2], bg_color=(0),
                                    size=vid2.size, ismask=True)
        # set mask to video
        vid2.mask = MASK_2 
        vid2 = concatenate_videoclips([vid2], method='compose') # combine with video


        # vid2.preview(audio=False)


        ''' ADD IMAGE TO THE VIDEO '''

        image_clip1 =  ImageClip(PIC1, duration=vid1.duration)#.resize(0.5)
        image_clip2 =  ImageClip(PIC2, duration=vid2.duration)#.resize(0.5)
        image_clip2 = image_clip2.resize(height=image_clip1.h)


        result1 = CompositeVideoClip([image_clip1, vid1.set_position(("right", "bottom")) ], use_bgclip=True)
        result2 = CompositeVideoClip([image_clip2, vid2.set_position(("right", "bottom")) ], use_bgclip=True)

        # add black area to left and right side
        def resize_vids_if_not_same_size():
            # add black area to left and right side
            m = abs(image_clip1.w - image_clip2.w) 

            if m%2 == 1: l,r = (m//2,m//2 + 1)
            else: l,r = (m//2,m//2)

            if image_clip1.w > image_clip2.w:
                result2 = result2.margin(left=l, right=r)
            else:
                result1 = result1.margin(left=l, right=r)

        print(result1.size, result2.size)

        # merge both the videos (vid1 and vid2 must be of same size/resolution before joining them)
        final = concatenate_videoclips([result1, result2])


        # final.preview(audio=False) 
        final.write_videofile(FINAL_VID)

    def download_pic(url, file_name):
        print('downloading picture ' + url)
        response = requests.get(url)
        if response.status_code == 200:
            with open(file_name, "w+b") as file:
                response = requests.get(url)
                file.write(response.content)
        else: 
            print('picture url was ERRORED')

    def download_loom(videoLink, vid_name):
        linkList = re.split("/", videoLink)

        videoId = linkList[-1]

        transcodedURL = "https://www.loom.com/api/campaigns/sessions/" + \
        videoId + "/transcoded-url"

        postRequest = requests.post(transcodedURL)

        deserialize = json.loads(postRequest.text)

        videoURL = deserialize['url']

        print("Downloading...")

        downloadVideo = requests.get(videoURL)

        with open(vid_name, 'wb') as f: 
            for chunk in downloadVideo.iter_content(chunk_size=255):
                if chunk:
                    f.write(chunk)

        print('successfully downloaded loom video')



    pic_url = 'https://api.apiflash.com/v1/urltoimage?access_key=02e0b0305fdc47d49c6a3bb7179f9358&url=https%3A%2F%2Ftwitter.com'
    pic2_url = 'https://api.apiflash.com/v1/urltoimage?access_key=02e0b0305fdc47d49c6a3bb7179f9358&url=https%3A%2F%2Freddit.com'

    download_pic(pic_url, PIC1)
    download_pic(pic2_url, PIC2)

    download_loom('https://www.loom.com/share/2ff13eb033584295b6389de7cdd1ae54', VID1)
    download_loom('https://www.loom.com/share/ac0957d8a75a4f9ba0b010be1ea457ae', VID2)

    generate_video()
    
    return {
        'statusCode': 200,
        'body': json.dumps(str(requests.get('https://google.com')))
    }

Yo! Found your gist from upwork, can you share what error you are getting?

First look issue -
Lambda doesn't have a directory structure like your local system.

# Change directory to /tmp folder
os.chdir('/tmp') _# This is important

Let's discuss this further. Here's my Upwork profile.