What is the difference between "let someone do it" and "let someone do it"

In the active voice, only the infinitive (prototype) of to can be used as the object complement.

For example:

Tom asked Jack to come and help him.

But in the passive structure, the infinitive symbol to should be added, that is, the infinitive with to should be used as the object complement, and its structure is as follows:

Someone is forced to do sth.

For example:

(Tom) forced Jack to come and help him.

Note: there is no structure that directly makes someone do something.

I wish you happiness!