I have A/B testing in my application with two variants.
The thing that I want to do is to set a specific user in a variant by myself(Like with his firebase token)I don't know how to achieve this.
I couldn't find anything in the firebase panel for it.
You can set / remove a variant to specific user by its FirebaseToken on Firebase Console.
In your A/B experiment, click Manage test devices
and determine a variant for a specific token.
Check out this documentation for more details. https://firebase.google.com/docs/ab-testing/abtest-config#validate_your_experiment_on_a_test_device