How to choose an artist and close a task like on Freelance?

Question

Ruby on Rails

In general, there are posts, there are responses to them, I’m interested in how to make the executor_id registered in the database and the status changed to performed, and the status:integer executor_id:references column in the posts table is tied to users
Please tell me how this is done?
Maybe there is a link with examples or in which direction to go ...