Sometimes, in the industry, it's not enough to know just how to code.
By learning UX Design, you give yourself a competitive advantage... instead of designing just to finish, you will first beginning with researching about the user and their particular needs, preferences, and motivations. This research, then guides your design choices... which in turns means you will make products/websites/apps that are relevant to the market.
UX design is something that many web developers pursue after they have learned how to code...
If you want to learn more about UX design, I recommend any of these online courses. They are great quality and the membership is low.