LiveChat website chat Failed to load resource

I’m not able to use Chat on my website

I installed LiveChat script on my website and I don’t know how to make this work.
I’ll post a print of console error on my browser:
What I should do to make this work?

Server Setup Information

  • Version of Rocket.Chat Server: 2.4.9
  • Operating System: Linux
  • Number of Running Instances: 1
  • NodeJS Version: v8.17.0
  • MongoDB Version: 4.0.3

Any additional Information

I’m using custom dns to my server.
Changed Rocket.Chat URL inside ‘General’ options.