What to use to create a web service?

Question

Computer networks

There is a desktop application for which you can write plugins in Python. I want to make it possible to save the results of the plug-in's work in a remote database to ensure the possibility of using (loading) the results of the work by another person / another plug-in. Those. I want to create a service for collaboration and use of previously obtained results.
I have no web development experience. You need to add a web service on the hosting with the site (wordpress). What is the best way to do this? Use xml--rpc, rest, soap? It is planned to work with the database clients in parallel with saving and receiving results. What architecture is optimal for my task?

Answer 1

Up to 10 clients. On the server side, I do not quite understand.

add api functionality for wordpress in PHP

is it to enable REST support in php.ini, write a php script with handlers and work with the database? How to connect it to WP? As a plugin?

according to the DB schema write python api

is it to use something like Flask? Like here: https://habrahabr.ru/post/246699/ ?
How much would a job like this cost to order on freelance?