How do I track equipment assigned to security guards?

Short answer

From the Pro plan, register every item (for example a radio, a flashlight, a uniform) in the equipment records.
Hand the equipment over to a guard through a handover recorded in the panel, with the person's name, date and time.
On return or when the holder changes, record the handover the same way, with name, date and time.
Enter the service date for equipment that needs periodic maintenance.
Open the list of equipment with a service due and schedule the service in time; 4guards sends no alert.

Law 319/2006 on occupational health and safety — the employer is responsible for the technical condition of work equipment used by guards.
Law 333/2003 on the protection of objectives — communication equipment (radios) must stay functional throughout the shift, to maintain contact with dispatch.

Example: a radio has its service date recorded. As the deadline approaches, the radio shows up in the list of equipment with a service due, which the dispatcher opens and then schedules the service without affecting coverage for shifts that depend on that radio.

Equipment handover between guards isn't confirmed, and responsibility for a fault stays unclear.
Service schedules are tracked on paper or not at all, and a faulty item ends up used in the field.
There's no clear record of who currently has a specific radio or other item.

Equipment records, available from the Pro plan, with handover to a guard and return recorded as a confirmation with the person's name, date and time, per guard.
The handover recorded with name, date and time shows clearly who received an item, so responsibility for a fault does not stay unclear.
A list of equipment with a service due, which you open from the panel ahead of the mandatory deadline; there is no alert and no message is sent.