Use a visible label, existing paperwork or a safe photograph from the normal access position. Do not move connected equipment to obtain a better angle.
What the observation means
A phone camera can help only where it can be positioned without reaching near wet electrics or sharp concealed parts. Unreadable information should remain marked uncertain.
A useful next step
Provide what is reliably visible and explain the limitation. The engineer can plan further identification. Do not guess missing digits or order a replacement from the casing shape alone, since closely related units may have different applications and connections.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.