The correct Active/Passive form of the given sentence is:

☀ Shouldn’t we honour the brave frontline warriors for their exemplary service?

Explanation for other options:

☀ Shouldn’t we honoured the brave frontline warriors for its exemplary service? This option is not grammatically correct. The correct form should use "honour" in the present tense, not "honoured."

☀ Shall we do not honoured the brave frontline warriors for its exemplary service? This option is not grammatically correct. The sentence structure is not proper, and it uses "do not honoured," which is not the correct form.

☀ Should we do not honoured the brave frontline warriors for its exemplary service? This option is not grammatically correct. It uses "do not honoured," which is not the correct form. The correct form should be "Shouldn’t we honour" in the present tense.