What should I do for my Lord to forgive my sins after I prayed in the Haram while I was menstruating, without my knowledge?

If you intended to pray during menstruation, you are not sinful if it was unintentional, because the Prophet, peace and blessings be upon him, said: "Indeed, Allah has forgiven my nation for their mistakes, forgetfulness, and what they are forced to do." It is forbidden for a menstruating woman to intend to pray.