Change WhatsApp to only one language (iOS)?

Hello,

I often find myself clicking on the globe in the bottom left corner. I don't notice it. I just notice that my keyboard suddenly doesn't have an 'Ö' key. I find that incredibly annoying.

Can you set it so that only one language is active? In my phone settings, I only have German enabled. I've already gotten that far. But I still have the globe, and it switches to English.

Does anyone know how to change this to German only?