Is it obligatory to make up missed prayers day by day, or is it permissible to divide the make-up over different times, knowing that one is sometimes able to make them up, and is it permissible to make them up during prohibited times?

Whoever misses a prayer is obligated to make it up. If they have missed many prayers, they should make them up according to their ability, without a specific daily limit, and without negligence. They should pray them at any time of day or night, at sunrise and sunset, and however much they can manage, whether a little or a lot. It is not sufficient to make up one day's prayers in a day; rather, one should make up two or more days' prayers in a single day. It is permissible to make up a missed prayer during times when prayer is generally forbidden, due to the generality of the Prophet's (peace be upon him) saying: "Whoever sleeps through a prayer or forgets it, let him pray it when he remembers it."