You didn't say what you wanted to use the tether for.

Assuming to keep it from dropping? I am using the Pixel 6 Pro version of this case.

https://www.amazon.com/Ringke-Fusion-Compatible-Shockproof-Protective/dp/B09F9WXGFF/

It has 2 spots near the bottom on the left and right for a lanyard/wrist strap loop. In my case I have added a wrist strap so that I can use my phone without worrying that I would drop it.