I might be hard to grasp, but don’t just talk about yourselves in the cover letter of your application.
I am screening quite some applications for our job opening - what is a surprise for me is the obvious tendency of people to apply using completely generic one-size-fits-all cover letters.
Tell me why you are interested in the position, and what makes you a good fit for the job’s requirement. Be specific. Make sure it does not sound generic.
Bonus points for being open on where you might lack experience or you have to replace knowledge with curiosity.
Be specific. Be open about things that are clear for the reader of your CV.