FDNY Commissioner Laura Kavanagh wants to “fix” the behavior of her department’s predominately male workforce — but can’t figure out how to extinguish their flames of discontent.

Kavanagh — who’s butted heads with plenty of male underlings since being named the city’s first female fire commissioner in 2022 — made the blunt admission while apologizing to New York Attorney General Letitia James during a March 8 text exchange, a day after pro-Donald Trump firefighters and other attendees mercilessly booed the Democratic pol during a department promotion ceremony.

“I should have called you last night, but I’ve been trying to find a way to say I’m sorry that doesn’t involve me apologizing for men who don’t deserve such grace,” texted Kavanagh, according to records The Post obtained from the AG’s office through a Freedom of Information Law request.

“I haven’t succeeded. I am sorry that we didn’t stop them and that I can’t fix them.”