Spritekit and swift - How to get data back from testers during testing

I'm building a 2d platformer that is level based. Game is built with spritekit and swift for the iOS Platform.

Each level has a "time" challenge. Basic bronze, silver, and gold medals. If you can complete the level by the times for the medals you will unlock that medal for that level.

When I send out a build for testers, I want to get data back that tells me how fast the testers complete the levels, so I can use this data to better judge what times I should set for the time medals in each level.

I'm curious how I would gather this information.

Having a hard time finding information on how to go about this.

Thanks for any advice!