Literally just do not turn the tv / phone on. Have other activities to do at home, we’ve had a similar issue as my husband was letting him watch tv every morning but I swiftly put an end to that once behaviour started to decline. Now, this morning my son has flicked through 10 books and played with his building blocks. Additionally my advice is practice what you preach and don’t sit on your phone while also saying no screen time 😁 good luck!
I know the feeling, I'm going with a slightly different approach of when she asks for tv asking her which show she wants to watch. Then depending what it is letting her have 1 or 2 episodes (usually hey duggy or number blocks so not really long ones but negotiating it before tge tv goes on) then the tv is off for a while we do x y or z. That way I'm cutting down the screen time as each day reducing the amount I'm saying yes to and the time between shows too. It's worked for us as we're nearly back to normal. And the asking has got less too. Either way you choose I'm sure you'll do what's right for you :)
We got a tonie box at Christmas and he rarely asks for the TV on now, it's great. Might work for you too there's always some on marketplace x
I only allow the tv on from 4.30 and it goes off at dinner by 5.30. I have an older child so difficult to go cold turkey but this seems to work to stop them asking for it all day. My older boy just knows when tv can go on and the little one understands when I say we can watch it at tv time later this afternoon
@Claire second the Tonie box, we also got ours at Christmas and it's working a treat, little one doesn't ask for tv half as much as before and when she does we redirect her attention to the characters etc
Might have to go cold turkey let her cry and lash out and just say no, after a while the novelty should ease off , Good luck