3D-printers come to the rescue.
Backbone Controller Official iPhone 13 Pro / Pro Max Adapter
BACKBONE One Mobile Gaming Controller for iPhone
Taylor Lyles on X: PSA: If you own a Backbone One and are
Backbone Adapter for iPhone 13 Pro and 13 Pro Max 3D Printed READ
iPhone Gaming with the Razer Kishi V2 and Backbone One - MacStories
Hardware Review: PlayStation Edition Backbone One Controller
Backbone Made a 3D-Printed Adapter, So Your New iPhone 13 Pro Will
Case-compatible modded, Backbone color-matched, 13 Pro/Max adapter
Backbone One iPhone 13 Pro & Pro Max Adapter : r/Backbone
Backbone's free adapter makes it usable with the iPhone 13 Pro