Hi I'm really sorry to hear you're struggling, how old is your child? And what's their wfh?
Food refusal can be challenged in a few ways.
You plate the food up, put it in front of them wort the expectation they will eat it.
You can either wait it out (depends on how much patience you have!) or time it for 45 mins.
If after 45 mins it's not eaten you could offer a meal replacement drink (ideally at more calories than the meal).
If you still get refusal, plate it all up and bundle them with the food into the car and drive to a&e.
Hopefully they will eat but if they don't see it through and get all the medical checks done.
Use whatever leverage you can, their phone is the obvious one but anything you can use to encourage them to eat is okay.
When they are eating distract distract distract, any which way you can, Tv, games, music anything to take their mind off eating.
Do not discuss the food, do not bargain with them, do tell them they have to eat the food - they have absolutely no choice in the matter, they can trust you.
It's hell but you can do this, the ED is a terrorist and it's holding a gun to your child's head. The only person who can take that gun away is you.