First time updating Heroku stack from 18-22, need advice

Hey everyone,

I'm looking for some advice on updating the Heroku stack for my app. It's been in production for over 4 years now and I haven't updated the stack since it was first deployed. I'm planning on updating it from stack 18 to stack 22, but I'm not sure if it's as easy as just pressing the stack update button or if I need to create a dev environment and test everything out.

I'm a bit nervous about updating the stack since I've never done it before and I don't want to cause any downtime for my users. I've read through the Heroku documentation on stack updates, but I'm still not sure if there are any pitfalls or things to watch out for.

Has anyone here gone through a similar experience? What was your process for updating the Heroku stack? Should I create a dev environment and test everything out before updating the stack in production? Are there any specific things I should be aware of or watch out for?

Any advice or tips would be greatly appreciated. Thanks in advance!