In Matthew 23:33 is one example. Granted I take it as more of a “if you continue down this path”. And according to the tenants of Catholicism God will only forgive the people who repent. You actually have to go to confession (or sincerely pray for forgiveness).
There are also a lot of people who can’t. There are lots of firsthand accounts of women who are the victim of rape or physical abuse and who can not conjure up forgiveness for their tormentors. Often these women get ostracized for their “refusal” to forgive, in some cases being condemned by their peers more harshly than the people who hurt them! Even when their tormentors never sought reconciliation or felt remorse! It isn’t a choice; sometimes the feelings are there, sometimes they aren’t.
When I mention the above article to people on this site, a lot of them say “I think this expert on the human mind is wrong about the human mind! I’m still gonna tell rape victims that they’ll burn in hell if they can’t forgive their unrepentant rapists”.
I will admit that a big reason why I don’t feel able to forgive the person I hate is because he never apologised or showed the slightest hint of remorse. I might have felt different if he accepted responsibility, but that isn’t the case.