Is it permissible for someone who owes fasting days to seek forgiveness, knowing that one of the conditions for the acceptance of seeking forgiveness is to establish Allah's religion?

Seeking forgiveness (Istighfar) is prescribed for all servants, including those who persist in sin. If one seeks forgiveness with their tongue without their heart truly abandoning the sin, it is a supplication (dua') that is hoped to be answered, while bearing in mind that this is not a complete repentance, as repentance cannot coexist with persistence [in sin]. Therefore, whoever has missed fasts to make up is commanded to seek forgiveness for their sins.