Step 1: Sit on all fours like a cat/dog.

Step 2: Suck in your gut and arch your back like a cat does when they are startled.

Step 3: Exhale

There is also a variation where you don't arch your back: https://hiitacademy.com/hiit-exercise-how-to-do-cat-vomits/

I basically found myself running out of things to try. My poor sleep quality was especially affecting me and I was desperate to get the reflux under control. And so I spent a lot of time thinking deeply about what could be causing my reflux.

It's difficult to explain why I thought to try this combination (fasting + cat vomitting exercise). It was sort of like I suddenly understood where the weakness was in my esophagus, and that this specific motion/exercise, in combination with giving my esophagus a break for 10 hours/day would relieve the reflux. I fully committed, and in not very long (3-4 weeks if I remember right), my reflux was mostly gone. Only had a few memorable reflux instances in the months that followed and now its been years since I've had any issues at all.

I still practice intermittent fasting 5 days a week but I don't do the cat vomit exercise. Part of me feels strongly that if I hadn't done both those things at the same time, I wouldn't have fixed my reflux, but obviously I have no evidence to prove that.

I also feel its important to mention that reflux has different causes. I felt like what I was experiencing, combined with all the reading I did about reflux, allowed me to settle on this particular regimen.

I am definitely not trying to suggest that this is some secret magical cure that big pharma doesn't want you to know about.

Sounds partly like marjari asana of hatha yoga.

Cat pose or cat cow pose.

Google it.

That does look the same/similar.

Web search says it's an abdominal breathing exercise where you are positioned on the ground on your hands and knees (similar to "cats and camels" for those familiar with that one).