How to get parents therapy

Ever since I was little, I could never go out with my parents without hearing a heated argument about something ridiculous.

All relationships will have arguing, but this is not healthy arguing. They don’t love each other. I see it in the way my mother always doubts every word that comes out of my fathers mouth, and how he shuts her out( he ignores what she says to him for his own reasons). I never spoke to them about it because its a sensitive topic. They never discussed divorce, but always threaten to leave(just randomly if an argument gets too heated)

The point is, how do I get them into therapy? I’m not so close to them I can talk to them about it they may take it the wrong way. They really need it. My mother has terrible insecurity and possibly has aspergers(she won’t go get a diagnosis) and my father hides it, but I’ve walked in on him crying alone. They don’t ever spend time together on purpose, only if I’m involved or they need to sleep.

Please, I feel like crying it hurts so bad to see my parents like this I don’t want this to go on. How can I get them to go to therapy? Should it be individual, or a relationship therapist?

Thank you so much if you help me. If you’re in a similar situation, I really hope things get better for you. Stay safe, everyone.