Is there anything in the Discourse API that can help you like a post?

Yes, see How to reverse engineer the Discourse API and Discourse API Docs

what is the “post_action_type_id”?

How can you like a specific post through the API?

Falco (Falco) April 20, 2022, 4:04pm 5

For like it is 2 as you can check via Reverse engineer the Discourse API

Topic		Replies	Views
Getting who liked a post from the API Development	7	3076	May 18, 2022
Get number of likes for a single post? Development rest-api	6	2194	March 20, 2023
How to unlike a topic or post Development rest-api	6	560	June 24, 2024
Discourse Likes API Development rest-api	6	1385	December 16, 2022
How to get the likers of the topic with api Product Support	5	1654	November 26, 2015