Languages: Added Greek keyboard to iPad. It doesn’t show up in apps.

In the settings, I added the Greek keyboard, along with the keyboard for German. In my messaging app, and other apps, there is an option to select English and Deutsch. There is no option to use the Greek keyboard. In settings, there is a checkmark next to the English and Deutsch keyboards, but there is no checkmark Next to the Greek keyboard.

how do I actually get to use the Greek keyboard that I added in settings? I looked for apps that might have a Greek keyboard, and there don’t seem to be any which have many reviews, so I don’t trust them.