That’s why it’s better to download as many apps as possible from F-Droid. All apps are Free Open Source and checked for anti-features (like ads, tracking, etc.). Lots of basic (and not so basic) apps which are ad free, tracker-free and free to advertise that way.
The answer is here, you don’t need to enable multilingual typing, you just need to add Heliboard as spell checker on your system Settings. Then, of course, choose the right language in Heliboard and have a dictionary for that language too