Ice Accumulating in Freezer

I have a Kenmore with French doors and pull out drawer style freezer.

Everything in my freezer is covered in Ice and it’s getting worse.

I had a guy over today (seems not too experienced) and he wants to replace the gasket on the door but I wonder if that is the real problem.

Anybody familiar with these?

I have water leaking in the freezer and gathering in the bottom of the freezer