The cover may protect the lamp assembly from heat, moisture and contact. Its condition should be checked against the model's instructions before further use.
What the observation means
A broken cover is different from a failed bulb. Glass fragments can also contaminate food or remain in inaccessible areas. Do not handle fragments in a hot cavity or substitute an ordinary household fitting.
A useful next step
Leave the appliance unused while obtaining compatible advice and arrange safe removal of any debris. If the manual allows owner bulb replacement, that permission does not automatically cover a damaged holder or wiring. Report which part is broken rather than ordering a bulb alone.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.