I *may* have just solved my sleep issues with kids the same age. Neither would fall asleep without me either. Mine are in the same room so maybe that makes it a little easier.
I bought them these flashlights off of Amazon:
https://www.amazon.com/gp/product/B01CXSZZ88/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 and then told them this is what all the big kids use to go to sleep. I put them to bed a little earlier and let them play with the flashlights (they do light shows, play music and are super easy to use). The flashlights have a timer so eventually shut off.
I told them they can play with the flashlights as long as they stay in bed.
I also hooked up our baby monitor again so I can talk to them through the camera. If they call for me I answer on that and try to convince them to go back to sleep. If they need something like water, I go up briefly, help them with what they need and then leave. I also tell them I will come check on them as soon as they are asleep.
So far it has really worked. I only allow them to play with the flashlights right before they go to sleep so the novelty is still there after 5 days. I think after a week or two they will forget about needing me in the room.
I would say, keep it positive and not like a punishment. Go in and reassure them if they need it but try to get out quickly. Tell them you have a lot to do but will be around if they need you.
Good luck op! Just remember consistency is key (even if they cry a little).. and once they start going to sleep on their own you will feel like a new person!