Why would you configure an OCSP responder URL in an end-entity certificate?

An OCSP responder URL in an end-entity certificate is used to designate a server for certificate status checking. OCSP stands for Online Certificate Status Protocol, which is a method of verifying whether a certificate is valid or revoked in real time. An OCSP responder is a server that responds to OCSP requests from clients with the status of the certificate in question. The OCSP responder URL in an end-entity certificate points to the location of the OCSP responder that can provide the status of that certificate.

References: https://docs.fortinet.com/document/fortiauthenticator/6.4.0/administration-guide/906179/certificate-management#ocsp-responder