Setup a coturn server

setup_coturn.sh

sudo apt-get install coturn
sudo systemctl stop coturn

sudo nano /etc/default/coturn
#TURNSERVER_ENABLED=1

sudo mv /etc/turnserver.conf /etc/turnserver.conf.original
sudo nano /etc/turnserver.conf
# see contents below

# create stun and turn DNS records

sudo turnadmin -a -u omgrtc -r openmedia.gallery -p 12345

sudo systemctl start coturn

# test here https://webrtc.github.io/samples/src/content/peerconnection/trickle-ice/

# Be sure that your server has the ports 5349 and 3478 open.

sudo ufw allow 3478
sudo ufw enable

##################################


# /etc/turnserver.conf

# STUN server port is 3478 for UDP and TCP, and 5349 for TLS.
# Allow connection on the UDP port 3478
listening-port=3478
# and 5349 for TLS (secure)
tls-listening-port=5349

# Require authentication
fingerprint
lt-cred-mech

# We will use the longterm authentication mechanism, but if
# you want to use the auth-secret mechanism, comment lt-cred-mech and 
# uncomment use-auth-secret
# Check: https://github.com/coturn/coturn/issues/180#issuecomment-364363272
#The static auth secret needs to be changed, in this tutorial
# we'll generate a token using OpenSSL
# use-auth-secret
# static-auth-secret=replace-this-secret
# ----
# If you decide to use use-auth-secret, After saving the changes, change the auth-secret using the following command:
# sed -i "s/replace-this-secret/$(openssl rand -hex 32)/" /etc/turnserver.conf
# This will replace the replace-this-secret text on the file with the generated token using openssl. 

# Specify the server name and the realm that will be used
# if is your first time configuring, just use the domain as name
server-name=ourcodeworld.com
realm=ourcodeworld.com

# Important: 
# Create a test user if you want
# You can remove this user after testing
user=guest:somepassword

total-quota=100
stale-nonce=600

# Path to the SSL certificate and private key. In this example we will use
# the letsencrypt generated certificate files.
cert=/usr/local/psa/var/modules/letsencrypt/etc/live/ourcodeworld.com/cert.pem
pkey=/usr/local/psa/var/modules/letsencrypt/etc/live/ourcodeworld.com/privkey.pem

# Specify the allowed OpenSSL cipher list for TLS/DTLS connections
cipher-list="ECDHE-RSA-AES256-GCM-SHA512:DHE-RSA-AES256-GCM-SHA512:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384"

# Specify the process user and group
proc-user=turnserver
proc-group=turnserver

Used from :

https://ourcodeworld.com/articles/read/1175/how-to-create-and-configure-your-own-stun-turn-server-with-coturn-in-ubuntu-18-04