Make a sentence with the word it's?

It's snowing.

It's been a long time since I last saw him.

Can you tell me whether it's ready yet?

She took the medicine an hour ago - do you think it's worked?

"It's" means "it is" or "it has". It does not mean "belonging to it". That Word is "its".

Therefore:

The dog has lost its collar (not "it's collar").

This company looks after its customers (not "it's customers").

And NB there is no such form as its'. Ever. In any circumstances.