@arubislander ok, Thanks for your answer.

@arubislander thanks your response, And I want to use multiple user in my devices, so I add a new user and set the password, but it doesn't work for passwd, I search many solved case ,but didn't work for me, could you help give some advise? thanks!

when I used command 'adduser' add a new user and change password by 'passwd' command, it show below error:
-- passwd: Authentication token manipulation error
-- passwd: password unchanged

and used 'journalctl -t passwd' check the log, show 'pam_extrausers(passwd:chauthtok): user "newuser" does not exist in /var/lib/extrausers/passwd', and i added the user info in the show path try passwd command again, and it can update the password show:
-- Enter new UNIX password:
-- Retype new UNIX password:
-- passwd: password updated successfully

but actually it doesn't work,can not use the password login the user, and i run again the command ''journalctl -t passwd'' , it show error "gkr-pam: couldn't update the login keyring password: no old password was entered", I don't know how to solve this error, any guys can help this? thanks in advance!

@arubislander oh, thanks, after formatted to FAT32, it works now.

Onepluse6T ubuntu touch can not identify USB， Is that a known issue for OTG not recognized？ anyone can help how to mount the external USB to device? thanks in advance！