Following password is legit I actually progressed so far in game on GameBoy Advance SP.
E. Tanks: 6
I can't beat Mother Brain without cheating.
You can also find maps for Metroid on this webpage https://www.nesmaps.com/maps/Metroid/Metroid.html
I recommend you use password generating only if you played through most of the game or in case you forgot password or passwords.
UPDATE (2.11.2019) - I found this site that does password generating https://www.truepeacein.space/