How to put this child to bed?

I babysitting my sister in laws friends 4year old girl, and she won't go to bed… Its 12:00 AM and every time i tell her she needs to lay down she keeps saying she's wants to wacth a different movie or play on her phone (yeah, she has a IPHONE… 4Year OLD… ) But I've fed her, i've played with her, i've got her in her jammies, and set up a little bed for her. Now we're watching spongebob movie and she's messing with her phone. How do i get her to lay down for bed?

Bribery? Eg If you sleep ill get you chocolate or candy or barbie

Put her phone away and read her a story.

Smack her upside her head with a frying pan.

This remedy always works for me:
Start to read a boring story and say ill be right back I'm going to the bathroom. Kid passes out waiting every time.

Tell her it's bedtime, take away her phone and turn off the tv. Tuck her in say good night close the door. When she comes out the first time with what ever excuse "I'm not sleepy " " I want water" or what ever tell her sorry its bed time and tuck her back in. Any more times she comes out of bed don't engage her simply take her by the hand and put her back to bed(it's ok to say goodnight when you close the door). If she has a tantrum pick her up and put her back to bed. Don't stay in the room with her or she won't go to sleep. Kids aren't dumb they know they can get away with whatever an adult will let them get away with and they will take it to the max. If you want her to go to sleep you have to make it clear that her demands will not be met and you are in charge.

She should nap in the afternoon for only an hour, any more later and it just makes her stay up later. Make her a bedtime for your house, use words and actions to enforce the bedtime.let her play outside in the yard or perhaps a park, then proceed to give her dinner, a bath and then put her in her jammies. With my godson I allow him to either sit in his bed and watch tv to unwind or I put him in his bed with his sippy and blanket with the lights off I play him music, He is usually asleep before I have to use the music method because he has no iPhone nor toys in his room.

You need tone strict with her. By giving in to her demands you are encouraging her to stay up. Why would she go to bed when she can watch SpongeBob and have fun? Think about it! You need to put her to bed, take away anything interesting from her room and keep putting her to bed until she gets the message.

Take her phone from her, turn the stupid TV off and put her in bed.

Why would they get an iPhone? When was that little, I got a DS And that was all lmao