Hello Mohsin,
I tried installing the test toolkit when creating a docker container using the syntax "-includeTestToolKit" in the code.
However, I seem to have problem downloading the Microsoft_Test_Runner.app.
Please see the picture below.

When to googling this problem, I found that I need a license file in order to fix this issue.
How do I get one if I am not a certified developer? I just develop as "a hobby" to learn programming.
Thank you for your help