Insomnia + Chat Rest Api + Fastpath

Good Day

I am using Insomnia + Chat Rest Api to join chat rooms and leave . . .

I want to implement PHP + Rest Api + Fastpath:

I tried to follow instructions on:

How to use fastpath with the chat api

but cant get first part even to work:

POST /restapi/v1/ask
POST http://mydomain:7070/rest/api/restapi/v1/ask

Gives me: 500 Internal Server Error

Anyone that could help me out?

Thank You

Albertus Geyser