First you have to install the revanced manager onto your phone.
Then uninstall the play store Reddit app if you still have it. And install a version of Reddit from here I believe you want a bundled version but it’ll tell you if that’s wrong when you try patch it with revanced.
Finally open the revance manager and find Reddit, click the patches you want - it’s quite limited still and you’ll probably only want to select the remove ads patch but have a read, there might be 2 or 3 you want. If there’s an error try downloading a slightly older Reddit apk.
Regulations are probably tighter outside China, can’t slap together a skyscraper in 3 months that’ll fall apart in a year like China can.