Save it off site in notes or spreadsheet or create a separate list
On a work's page
ON PC: right next to the stars for rating [add to list]
ON MOBILE: underneath the rating stars [add to list]
Be careful and make sure each list is properly being entered into the list
Maybe to be extra safe, list each work you added to the list down in your notes app
I think the site is more stable now, but I talked to people that were having issues adding photos to their albums + adding stuff to their read/reading/want to read and that stuff was disappearing.
(I say to be careful and list it because we thought adding photos to your albums was safe, but it was glitchy yesterday.)

How can I save my manga/manhwas on my history? Is it not possible without marking them as "read, reading" heeelp