If English is clicked then store English as the language and use another tag to store ‘true’ so the app knows that this option has been selected already and not to show it again.
Use Another Tag in TinyDB to Store the Preferred Language.
Suppose it is - PL
When Your App Initialize - Check if the TinyDB has PL Tag.
if it is Present then Don’t show your Language Selection Page,
And get Value of PL Tag to Know what Language to Use for the App.
if it is Not Present then show your Language Selection Page,
And when the User Clicks on Any Language Button, Store that Preferred Language under PL Tag in TinyDB.