1ctx is a NextJS artifact.
2
3ctx is a context object containing those properties (Source):
4
5pathname - path section of URL
6query - query string section of URL parsed as an object
7asPath - String of the actual path (including the query) shows in the browser
8req - HTTP request object (server only)
9res - HTTP response object (server only)
10err - Error object if any error is encountered during the rendering