Why I get empty array in respose to People API in Microsoft Graph?

Question

Hello. I'm trying to get list of peope using People API in Microsoft Graph.
$persons = $graph->createRequest('GET', '/me/people')
->execute();

But I receive empty array as response.
I have some recent emails in my emailbox and I need to find all the contacts I sent an email, or all contact that has sent email to me?
Is it possible todo by People API, or maybe with some another API?

thank you