Is it permissible to supplicate for a change in one's foreordained and decreed condition, while being content with Allah's decree, and how is an unalterable destiny distinguished from a contingent one?

It is permissible for a servant to ask their Lord to change their condition from bad to good, for supplication does not contradict contentment. Contentment comes after the divine decree, whereas supplication is a request for a future matter or to ward something off. Supplication can avert a suspended decree but does not change an absolute, predetermined decree, as absolute decrees are not subject to supplication. Divine decree (al-Qada' wal-Qadar (definition)) is an unseen matter known only to Allah, and a person should ask their Lord for good and have a good opinion of Him.