how do I cancel a purchase? purchase name is screen mirroring Z should have 3 days free.

Hi there, Kentcora! Thank you for posting your question to the Apple Support Communities. We understand that you would like to request to cancel this App Store purchase and we can certainly point you in the right directly for help. 

To request an App Store refund, please follow the instructions from the Apple Support resource that we’ve included below. 

Request a refund for apps or content that you bought from Apple

We hope this information helps put you on the right track to a resolution. Please let us know if we can help with anything else. 

Cheers!