Manager users are managed under Settings → Users, in the Administrators section. Some details there you can change yourself. Others, including the login email, have to go through VoiceERP support.
What you can change yourself
Press the pencil icon on a user's row to open the Update Admin dialog. You can edit:
their phone number
their Linked driver (optional), which connects them to their own driver record
which pages they can open, using the access checklist
Press Update to save. You'll see "Admin updated." when it works.
The Root user's row, the account created when your company was first set up, can't be edited from this list. Its pencil and trash icons are grayed out.
Changing a login email or a name
The Update Admin dialog shows the person's Name and Email as read-only text. You can't edit either one in VoiceERP.
To change either one, contact VoiceERP support. Include the person's current email and the new name or address you want. This applies to your own account as well as to other users, since there's no separate profile or account page to edit yourself.
Profile pictures
VoiceERP doesn't have profile photos for manager users. The circle in the top-right corner that opens the user menu is the same for everyone, and there's nothing to upload.
Passwords
A password isn't something you change in Settings. Use the Forgot password? link on the sign-in screen to set a new one.