Nodejs api with oath2

Situation
Hello I’m new to openemr and I want to get patient data through nodejs using standard api but I don’t know much about aouth2. when I saw instructions I understand that I should have front end to redirect user to it.
my application is a back-end only and I don’t know how to get around it.

OpenEMR Version
I’m using OpenEMR version 7.0.2

Browser:
I’m using: firefox

Operating System
I’m using: Linux Ubuntu.
openemr installed on docker.
Search
Did you search the forum for similar questions?
Yes and didn’t get any information about it.

Use the client credentials grant if you are a backend only application. There are lots of articles on the internet on how the grant flow works for client_credentials. The specific technical specifications for running the grant is in our API documentation.

First of all, thanks for replying.
can you give me a url for both please?
I opened client credentials grant and saw that it’s provided by microsoft