Is screens replacement covered under my warranty

The warranty covers manufacturing defects. If you have damaged your screen yourself it is not covered.

Here is the warranty text for the US:

Apple One (1) Year Limited Warranty

WHAT IS COVERED BY THIS WARRANTY?

Apple Inc. of One Apple Park Way, Cupertino, California, U.S.A. 95014 (“Apple”) warrants the Apple-branded iPhone, iPad, iPod, Apple TV or HomePod hardware product and the Apple-branded accessories contained in the original packaging (“Apple Product”) against defects in materials and workmanship when used normally in accordance with Apple's published guidelines for a period of ONE (1) YEAR from the date of original retail purchase by the end-user purchaser ("Warranty Period"). Apple’s published guidelines include but are not limited to information contained in technical specifications, user manuals and service communications.

A standard warranty does not cover physical damage such as broken screens.