When you want to invite a lot of users, make a bot, give it admin permissions and then run this.

Discord Invite Bot

import time
import requests

DISCORD_API_URL = 'https://discordapp.com/api/v6'
DISCORD_API_SECRET = 'Bot ...'
WELCOME_CHANNEL_ID = YOUR_CHANNEL_GOES_HERE
COHORT_SIZE = 1000

headers = {'Authorization': DISCORD_API_SECRET, 'Content-Type': 'application/json'}

def create_invite():
    payload = {
        'max_age': 0,
        'max_uses': 1,
        'temporary': False,
        'unique': True
    }
    r = requests.post(f'{DISCORD_API_URL}/channels/{WELCOME_CHANNEL_ID}/invites', json=payload, headers=headers)
    if r.status_code != 200:
        print(r.status_code, r.json())
    if r.status_code == 429:
        time.sleep(r.json()['retry_after']/1000)
    return r.json(), r.headers

def append_invite_file(invite_code):
    with open ('invites.txt','a') as f:
        f.write(f'https://discord.gg/{invite_code} \n')

def rate_limiter(headers):
    wait_time = float(headers['X-RateLimit-Reset']) - time.time()
    if int(headers['X-RateLimit-Remaining']) == 0:
        if wait_time <=0:
            wait_time = 0
        print(f'Rate limit, Limit: { headers["X-RateLimit-Limit"] }, Remaining: {headers["X-RateLimit-Limit"]}, Reset: {wait_time}')
        time.sleep(wait_time + 0.1)

def main():
    for i in range(COHORT_SIZE):
        invite, headers = create_invite()
        append_invite_file(invite.get('code'))
        print(i, invite.get('code'))
        rate_limiter(headers)


if __name__ == '__main__':
    main()