i've setup Joplin server on my NAS serveral days ago.
now i can not remember the password of admin@localhost.
how can i reset the password?
If it was a random password with high entropy : good luck !!
if it was one of those passwords which you either re-use many times, with or without a little change ... say, like churchbells, churchbells+ churchbells&3 ...
then your best chance is to think about it, and then try a few of those derivatives. It has worked for me in the past.