Duh. Shoulda looked it up in the first place. There's a few ideas here:

https://www.quora.com/How-do-you-prevent-your-catalytic-converter-from-being-stolen

Related
What is the best anti-theft measure I can do to help prevent my catalytic converter from being stolen again?
Couple ideas that May help with this problem, an it is a growing problem that needs to be dealt with. Oem cats are a very expensive item to replace, and the aftermarket ones are not worth buying imo.

vin etching into the cat-contact your dealer to see if they offer this service

bbq /high heat paint on the cat assembly

weld a rebar cage to the exhaust system

weld sawzall blades along the length of the exhaust

shape tool steel/drill rod to the exhaust and send it out for hardening, then weld it to the exhaust

skid plate/cat shield

there are some products designed to lock around the catalytic like cat-lock

dash cam with good night vision and parking mode is always a great idea

Don’t leave your vehicle unattended.