Teamleader CRM APIs authentication and Authorization

We have a Teamleader CRM account. We can access the APIs using Insomnia but we have to get the bearer token using C# or ASP.NET core application then need to consume the teamleader APIs. Here we have client_id, client_secret, and others information as well. We have to use oAuth 2.0
This is the Teamleader API documentation link:
https://developer.teamleader.eu/#/introduction/authentication

It's an urgent task if anyone can do this task, We can give more task.