Moving unmovable apps to SD Card
https://play.google.com/store/apps/details?id=com.gmail.heagoo.sdcardmovable
open the app,
goto "only ROM" tab,
press and hold the app,
tap "make it movable",
"uninstall" (the original app),
"install" (the patched apk),
then check again from your app settings if the "change" (storage) button appears.
Note: the app will no be longer updated from Playstore. You lose all app data on uninstall