I am using REST API in C# in Visual Studio to create a test case in Azure Test Plans and after I would like to add that test case in a test suite still using C#.
Does anybody have any idea how?

Already tried this and I get this response –
The controller for path ‘/ProjectName/_apis/testplan/Plans/123123/suites/43243/testcases/156719’ was not found or does not implement IController.

        string addToSuiteUrl = $"{azureDevOpsOrganizationUrl}{project}/_apis/testplan/Plans/{testPlanId}/suites/{testSuiteId}/testcases/{testCaseId}?api-version=7.1";

        var suiteContent = new StringContent(string.Empty, Encoding.UTF8, "application/json");

        var suiteResponse = await client.PostAsync(new Uri(addToSuiteUrl), suiteContent);