T-Seps for Apple/Mac is not compatible with the M1 processor. The reason is that Photoshop 22.3 (and higher when released) has removed Extension Panels from their M1 version and T-Seps runs in the Extensions panel. T-Seps 4.0 will be Mac M1 compatible. Details on release date HERE.
The good news is you can open Photoshop in Rosetta mode to run plug-ins like T-Seps to in Photoshop on the M1 processor.
Here is a link to an Adobe website with details about compatibility and other issues with Photoshop and M1. And, this page has a link to details about running in Rosetta mode. Click HERE.