Email invitation is the usual route: send an invite to a new team member's email address and assign them to a user group before they've even signed up, so their permissions are correct from their very first login.
Manual account creation is the alternative, useful for bulk onboarding or when an email invite isn't practical — an administrator creates the account directly and shares the login details.
Either way, set a default department for the new user so their incident forms are pre-filled with the right context rather than starting blank every time.
On first login, a new user sees a simple guided view of the incident form and their assigned locations — enough to start logging incidents immediately without needing a walkthrough first.