@EmptyBites that's the hardest thing to overcome with kids like that... I had one of those. Nothing really worked because she simply wasn't hungry.
I'm on the other side of it now and ironically not only does DD feel hunger now that she's older, she even gets hangry.
What I did (half of it wrong by today's/professional standards). Set meal times every single day , when she first started signs of hunger it was around the times she would normally be fed,especially lunch.
Small portions, but she had to eat more than when she said she was full(never full plate). So if she was "full" after 3 bites, I asked her to do 3 more, or one more carrot, or to this line.This increased in time.
Snacks on offer all day,if she wanted it she could have it, but often needed reminders.
We also had cartoons on and yeah it was painful "keep eating" "I am" "chew" "i am" "swallow" "I am". Took fucking ages.
Some kind of reward /exciting activity for after so that she would hurry up a bit. Again with reminders. "I'll play guess who with you after dinner,but look it's already 5:20 and you're going for quiet time at 6, so it's up to you how long you want to play for". Or take an ice lolly out towards the end and say she could have it, but she had to hurry otherwise it will melt. Yes I'm a dick.
As she grew she had a set time in which to eat ,then food would go. It worked really well with the foods she really loved. In time it became habit and nothing took an hour and a half anymore.
She mostly got offered things she actually liked /enjoyed the taste of. So she got "something " out of it.
We had the same issue, she was never hungry, she'd rather chat,sing,play ,count the white dots on the ceiling.
On top of that she was fussy as fuck too. The kid was 3 before she accepted pancakes as a good thing. At her worst she had two weeks with a bag of crisps (the small multipack ones) and an icecream a day.
Eventually we made progress and she eats a lot better now,in a reasonable amount of time ,doesn't need a screen or a treat/reward anymore and like I said,the most important thing she actually gets hungry which helps enormously. It took a lot of work,a strict routine, and probably many mistakes on my part.
I still get flashbacks/get really worried when she's ill and barely eats in case we go back to that.