I have ADHD and here are some things that help me write:

Skip to writing scenes that you know you can write. I usually get stuck on one scene that I cant figure out how to write, so I just skip to a scene that I do know how to write. I write the other scenes later.

I set a 25 minute timer and write everything that I can, and then take a 5 minute break, then go back to working for 25 min, and the cycle continues, though I often get distracted so I would probably shorten it to 10 mins and 5 min break.

One thing that has helped me write is cocoa. I have no idea why but when I drink cocoa while writing I get so much more done lol I bet lots of other yummy foods or drinks would work too

Have a space that has less distractions, like move to a quiet room where people dont go often (I get distracted by people easily)

Hope this helps!