mormegil

https://en.m.wiktionary.org/wiki/Appendix:English_contranyms

It’s not as easy as it sounds, sometimes the screens are all wrong!! https://xkcd.com/722/

Yeah, that’s why unlocalize.com exists (or… existed? Dunno, seems down from here!) Or you can have used the official Microsoft Language Portal… until they removed it and replaced it with the worse https://learn.microsoft.com/en-us/globalization/reference/microsoft-language-resources (but it’s still usable, I guess…)