Update I played around with a new parameter with some user agent info for a few minutes, think I am missing something simple. When I do get it working it will require making a new settings page option in WP Admin to fill in user info so might as well add some of the other options. It will be awhile since I am gaming more lately.
I have removed the post with plugin download due to an API change that I need to make adjustments to. Chess.com made a change for user agent requirements and if none is used then an error and no data will be grabbed. I will look into what needs to be done and possibly make an update in the future. It appears I will need to add some user identification options, meaning a menu in WP admin/settings.
Many sites/services have been trying to reduce costs and API access to the public is being limited or removed, I don’t blame these websites one bit either. My older version of this plugin was just a simple snippet made in minutes that would make an API request each time a page on your WordPress site with the short code was on. This should have been done with limit on fetching data saving data to user meta built into WP, was planned for a new update. I only code PHP stuff from time to time. Added more info due to how many hits this post gets.