As stated you will find them at most hardware stores.
I got tired of that dog & pony show, I had replaced the clips more than once from coming loose and or breaking I also got tired of the screen rattling while going over bumps.
So I decided to remove the screen and take some black silicone sealer and put very small dabs all four corners and one dab on each side reinstalled the screen and tape it in until it dried and removed the tape after 24 hours to dry.
That was a few years ago never came loose and the best part is ....no more rattles, should I decide to remove the screen for whatever reason? the screen can be removed easily with a small plastic pry tool such as these.
https://www.ebay.com/i/292196345404?chn=ps&dispItem=1
Put black plastic screws on the holes to finish it.
Remember use only very small dabs of silicone....otherwise, all bet are off as for getting it out.
Happy Trails