Kowa TSN-CM2 T-Mount Camera Adapter Ring (Canon EF)

Yes, that is exactly what I use with my canon rebel t7i

The T adapter is 42×0.75 (42 mm diameter, 0.75 mm thread pitch) 42mm = 1 21/32 inch

No, the Kowa TSN-CM2 T-Mount Camera Adapter Ring (Canon EF) is for EF mount not RF mount. This will work direct onto a Canon RF camera, https://bhpho.to/3JROjqV.

To mount Kowa TSN-CM2 T-Mount Camera Adapter Ring on your camera I will recommend attaching it first on your Spotting Scope 2- Matching the red dot on the adaptor with the red dot on your camera lens mount. 3-turn your spotting scope clockwise until you hear a click To release it from the camera just press on the camera lens release button. turn the Spotting Scope while the release button is press down.

Correct you need a "camera mount" to attach to your scope Than these (2) parts screw toghter. The camera mound will depend on the make and model of your scope.

First you need an SLR camera adapter where the eyepiece would normally be attached to the telescope, then screw the T-mount adapter to the opposite end of the SLR camera adapter. then attach your camera to the T-mount and you are ready to begin taking pictures! The T mount adapter you are asking about is the correct camera mount to use your Canon camera on the telescope.