What is the standard Dragon Flag Progression? How do I get started?

Title says it all please I really want to learn the dragon flag and have scoured the internet for videos showing progressions but they are all decently complicated and contradict each other. If anyone can give a solid post/video of the progression to the dragon flag it'd be greatly appreciated.

Also, any ideas as to where I can do the dragon flag I'm struggling to find a good place to actually perform the dragon flag because clearly you need a stable support that won't move or give out?

Thanks to everyone in advance for helping me out. I'm excited to get all the strength gains in my core! I love Bruce Lee lol.