Rusting inside microwave cavity

Haste

Proxy Warrior
Explorer
Inside cavity of my microwave has started rusting in the back edges.

Its just 3-4yrs old so don't want to discard it yet, so was thinking to have it painted to squeeze few more years. But I'm not sure what kind of paint to apply.

I searched online, in other countries they get a specialized paint for it which although is available in India but costs almost 50% of what new microwave will cost.

Can anyone suggest what type of paint i should apply?