You can order it, but installing it is tricky. If it's your first time attempting to micro-solder and/or don't have the needed tools and/or don't want to risk ruining anything on your phone, I say have someone experienced get it and install it for you.
1/ Capacitor, 56PF 5% 16V NP0-C0G, 01005 package.
2/ digikey.com, mouser.com
3/ Look up [https://www.ifixit.com/User/739239/jessabethany|jessabethany] if you're in or near the US. Let me know if you're somewhere else.
Good luck!