Sign in as the local owner
Use /admin/master/login.php on your Desk domain with the owner account chosen during installation. Keep this account available for administration. Orbit accounts and customer portal accounts are separate from staff sign-in.
Give each person an account
Open Configuration → Team & Access to manage staff. Use Roles & Permissions to review the actions a role can perform. Assign only the access needed for that person's work. Menu items depend on permissions and enabled modules, so a limited staff account can see fewer options than the owner.
Use separate accounts for the people handling cases, quotations, recruitment and system configuration. Avoid sharing the owner's password as a way to give somebody access to one queue.
Check the result
Sign in as the intended staff member in a separate browser profile. Confirm that they can open assigned work, send the intended reply and use the required screens. Also check that unrelated configuration and private work remain inaccessible.
Blocking staff access keeps the account, assignments, messages and history. Password changes invalidate older native sessions. Review retained local accounts and passwords before adopting a release on an existing installation; an old password remains a credential until you change it or disable its account.
For customer access, use the separate verified-email request journey.