I think another comment already said what I was going to suggest: get a router with family controls. I use an ASUS. It works, but it’s not really easy to use. Newer models or other companies might be easier.
This is self-hosted. So you could also consider OpenWRT. It’s not user friendly, but it’s powerful.
“I’m a bun“ song: https://www.youtube.com/watch?v=gOKY52MM3p4