7 y/o refuses to play independently

Hi all, as the title states my NK B7 refuses to play independently. A good example is if I have to put his sister down for a nap (age 2) he’s like “well what am I supposed to do” and argues for a screen, even if he knows it is not a screen day. He will become angry and rude when denied the screen or redirected to any of the MANY toys and games he has to choose from. It’s also just exhausting because when I have both of them it can be difficult to find an activity due to their age gap, and he becomes upset if we do something she wants to do. G2 can happily play independently, she doesn’t always, but she does at least have the ability and enjoys it. Maybe this is more of a cent? Or I’m looking for ways to subtly encourage independent play for B7? Help lol