Same way you access any other chapter you have written. Just go to your list of chapters and look for the one you saved as draft. Alternatively, you can go to the story the new chapter is for, and find it there.
Check in recently deleted if you wrote on a story you do not own. There sadly isn't any notification for deleted chapters. Don't know if it works for drafts though. On last resort message Friedman and tell him where they were, he might be able to get them back for you.
Thank you ,already wrote another chapter as a replacement for the one i lost,t is being reviewed now anyway thank you.