Does a staff member I invite need to create their own password?

No. With an invite, they set their own password.

1. Go to Settings → Roles & Permissions → Manage Staffs and click Invite staff.
2. Enter their Email. This is required. Pick a Role, or leave it as No role (set later).
3. Click Send invitation.

They get an email with a link. Someone new to Wcart enters a Full name, a Password (at least 8 characters) and Confirm password. Someone who already has a Wcart login clicks Accept invitation, signing in first if asked.

The link works for 7 days. Until it is used, the invite shows under Pending invitations.