times when divorce is allowed:

a partner cheats on their spouse/commits adultery/fornication.

any kind of abuse, mental, physical and spiritual, and not just a one time abuse obv but also long time abuse.

the relationship between the 2 people can't be repaired and is broken to the point of no return sadly, to the point where the relationship is hurtful for both parties and is a awful toxic relationship.

divorce is the very last thing you should do. the first thing you should always try to do is repair the relationship and try to do anything other than divorce.