I found 2 pseudo ways:
Easier and reliable: Just share the movie link with some app that you can delete later, eg.: share it with whatsapp (better if you have a 2nd cellphone to do that), but then you have to use an external app.
Tho, the best app I found for this is "Keep notes": create a label on it "Watch Later". On netflix app, share the link to keep notes with that label. On keep notes, search notes with that label.
UNRELIABLE (I kept this here so you can try, but as soon the netflix app restarts for any reason, the "pseudo watch later list" will be lost, unless they "fix" it...)
more complex, inside netflix app (only works with videos that can be downloaded):
1 - opt to download videos
2 - opt storage as the external sdcard
3 - fill up sdcard with trash (like a copy of 100MB files, i suggest using x-plore to make copies) in a temporary place that is easy to delete later (the trick step)
4 - try to download a video, it will fail, the item will remain on the download list as being unable to download it, won't use storage space, it is pseudo-perfect :), the item will remain there (let's hope they dont change this...)
5 - before watching or downloading, just delete some of the trash if needed
Obs.: starting a download and pausing it only allow us to "continue all downloads" after, what is messy.
any more tricks?