Why doesn’t my friend want to leave her house??

It’s summer!! And I want to hang out at the beach and ride bikes and have fun. All she wants to do is stay at her house, she’s so boring. And her life is so awkward because she is 19 and she lives at her boyfriend’s friend’s parents house..... that’s so weird!!!!

And she’s mad at me for not wanting to go to that house. I’m sorry like that is extremely uncomfortable.

How do I convince her to leave the house? She says I’m a bad friend and blah blah blah for not going to “her” house. I’m like that’s not your house, you’re just there because you don’t want to pay rent.

I just want to have fun with her but she’s so extra. Why would anyone want to be home during summer?

How do I get her to leave the house and actually do something fun? She says she doesn’t want to do anything besides me hanging out at that house. She says it has nothing to do with covid19, it’s just sees mad at me for never wanting to go to that house