The flap is part of the intended compartment arrangement, not merely a cosmetic cover. Damage can affect closure and the storage conditions around it.
What the observation tells you
A missing catch or cracked hinge may let the flap sit partly open. Forcing it shut with tape can hide the damage and interfere with ordinary access. A shelf or container placed against it is not a reliable substitute for the correct fitting.
A useful next step
Identify the model and the affected hinge or catch. Keep food in storage appropriate to its needs while suitability is assessed. Ask for a compatible replacement rather than modifying a similar-looking flap.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.