Problem in mounting WebDav disc

I’ve got a home cloud for the family members : NextCloud on Debian.
The Cloud as :

  • an administrator with no data stored on the cloud
  • 5 users storing their datas
    To ease the use of the cloud at home, I try to mount a WebDav Share.
    If I follow the guide I’ve got to create users account for each NextCloud user and then put a secret file in each home directory.
    But when I try to mount or when the server restart, it’s with an other account. So the mount command can’t find the secrets file and the mount failed.

To illustrate :

  • toto is the default user on Debian
  • titi is the NextCloud user that wants a WebDav Share
    When the server starts it’s with toto’s account and the secrets file is in titi’s home directory.

Thank’s in advance for your pieces of advice