API key error

I am facing this issue with trying to enter API key for challonge wordpress plugin – Every time I try to enter the API key , it tries to verify and then gives an Error -> “Sorry, an error occured!”

I am unable to figure out whats happening

Error in console log ->
load-scripts.php?c=1&load[chunk_0]=jquery-core,jquery-migrate,utils,regenerator-runtime,wp-polyfill,wp-hooks&ver=5.9.2:2 GET https://www.noidatabletennis.com/wp-admin/admin-ajax.php?action=challonge_verify_apikey&api_key=CPPwK8UdnpZBNfdlrrBKE7u15qUKiXMVuO6if6SR&_fs_blog_admin=true 500 (Internal Server Error)

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