Make iOS stop opening MS Word files in Pages

I understand from a previous thread how to stop this bad behavior on a Mac. The solution has to do with selecting a .docx file (without opening it) and Get Info, and then change the Open With option. The problem is that I don’t know how to change that option in iOS Files app. There, you can get the info on a file, but you can’t change any of that info. Help, I use my iPad Pro as a laptop and now I can’t open any file from Files app without launching Pages. Maddening.