Use Reddit API in PHP or Command Line Curl to post a new comment (to existing thread)

I'd like you to set up a minimal PHP script or just command line curl command to post a new comment to an existing thread.

I already provide:
- user/ password
- token (from Reddit OAuth)
- comment id (i.e. t3_dfjgjgk)
- comment text

This post may be helpful (though ultimately it did not work for me)

https://stackoverflow.com/questions/71860914/php-curl-reddit-api-submit-to-subreddit

I will only accept your solution if you:

a) create your own app/ token
b) post a new comment (as show in screencast)
c) provide a minimal documentation so that I can use it

Thanks so much!