How do I replace a broken key on a logitech keyboard for iPad?

My "R" came of and I do not know how to put it back on. My iPad keyboard is a amazon keyboard. Does this mean that my keyboard is broken or will I still be able to fix it? I will be waiting for an answer. Hope you understand. Thank you.

Spare keys for some of the Logitech keyboards are available but not from Logitech which is a pity. It does not help when people and even suppliers bother to define the exact keyboard model!