Set the "What to test" in TestFlight


i’ve automation to create new build after every merged PR, and i’m looking to add the PR name into the what to test field in TestFlight. I currently trigger my TestFlight uploads using the Fastlane Pilot step, which is triggered from Bitrise, and was wondering if there is a way to either just upload the build with the regular “native” step, while passing the “what to test” field, or somehow pass a param to my current (in-project) fastlane step so it will be read and set from there.

Any help will be appreciated!