crack at the bottom of my screen macbook

@kaz-k is absolutely correct Apple will charge you $500+ US.

You could cut a piece of black electrical tape to size to place over the area to try to keep it intact and to hide the crack. You can always choose the expensive Apple repair at anytime if the problem gets worse (Apple fully supports Macs for 5 years and possibly for another 2 years if parts are still available).

I have removed the cracked Bezel and installed replacement Bezels so that is an option if you can find an independent repair shop willing and capable to do the Bezel replacement. It is a tricky procedure since there are lots of very fragile & delicate flex cables just beneath the Bezel which can be easily damaged. If these cables are damaged, then you will have no choice but to pay for the expensive Apple repair. I can tell you from personal experience that even with my experience in this area removing the old Bezel can be tricky. A repair shop specializing in iPad repairs may have the skills to replace the Bezel as iPad repairs require similar skills in removing the iPad glass.

That crack is cosmetic and the piece has no function other than to look good and possibly afford some protection for what's beneath. But, that's important too for may people. Considering the likely event of damaging underlying cables and such, and the cost of such a repair, I'd just live with it. But, that's just me and I certainly understand the situation. It's like getting that ding on your new car and I've lived through that many times.

Hi,

I think it's not covered by one year limited warranty, so if you try to repair it, they will charge you an "outrageous" fee.

Anyway, you'd better contact Apple Support and ask about it.

Official Apple Support