I hope you are doing well. I have some questions or rather a guide

I just finished a training in SQL, and I chose PostgreSQL as my DBMS.

Before I start, I'll give you a briefing to put you in the context:

I am developing a Windows Desktop application (with Flutter), this application will be a local application that will run on several machines.

And all instances of the application installed on the different machines will fetch data from my PostgreSQL database.

So, instead of making a direct interaction between the database and the application, I want to set up APIs that will take care of the interaction between the database and the application. The application will send an API request and the API will interact with the database and return the response to the application... (Of course you already know what an API is and what it does).

The Desktop application is a local application, the database will be on a local machine/server which is on the same network as all the others.

So my question is if it is possible to do this, to make local APIs only that will interact with my local database and local application. If so, how do I go about it? What are the tools I need to learn to use or have.

Thank you!

P.S: I hope I was clear enough in my message (everything was a blur in my head). I did some research on the internet but nothing that really explains what I need. I am still a beginner

Sorry for the long message