The Sentences which express request, order, advice, suggestion, prohibition etc are called imperative sentence.
The imperative sentence in the passive voice has the following structure:
Let + object + be + past participle
When the active voice begins with do not, the passive voice has the following structure:
Let not + object + be + past participle
1.Examples are given below:
Active: Open the window.
Passive: Let the window be opened.
2.Active:Do it at once.
Passive:Let it be done at once.
3.Active: Do not write stories.
Passive: Let the story not written.
4.Passive: Let me be helped.
Passive: You are requested to help me.
5.Active: Don’t use it.
Passive: Let it not be used.