Potty training help!

I need some help! My son will be turning 2 on the 19th and lately he has been fighting me to wear diapers/pull ups. When I try to put them on him he says “I sit on the potty” but then refuses to sit on the potty. He’s peed on the potty twice and had a couple accidents when going diaper free but it doesn’t phase him. He just says he’s got water and continues to play no matter how much o tell him pee goes on the potty.

The thing is he will tell me pee goes on the potty and when he’s peeing and pooping but doesn’t want to go on the potty unless there’s people here for him to show off to!!

I’m having another baby due August 6 so I was hoping to not have to keep buying him pull ups