finite element method analysis programming on matlab

I need to solve this fem problem using MATLAB...I have a half-built code for this problem, and I want this code to be edited so the entire code structure looks similar to my code, but it works for our problem. I have been following this playlist to code until now:
https://youtube.com/playlist?list=PLnT2pATp7adU_OYwrPoDWE_YmePxu-fMf