You can use someone else’s smartphone with Google Translate app on it, enable the camera in the app & use it to scan your FGO screen (on your device). Hopefully the app’s camera would be able to discern & properly (I doubt it) translate the JP text on the screen. I use this sometimes cuz basically I can’t copy/paste nor type the similar JP text onto somewhere else
Actually, Google Translate app can scan a screenshot, so you don't need another phone to do the job, unless you are just lazy to switch in-between apps.