CSR vs Direct Public Key Exchange: When Do You Really Need a CSR?

When working with secure systems, a common scenario involves Server A obtaining a certificate signed by Server B (acting as a Certificate Authority, or CA). But if the ultimate goal is to exchange public keys so that JWTs (JSON Web Tokens) signed by Server A can be verified by Server B, you might wonder: Do I really need to use a CSR (Certificate Signing Request)? Can’t I just send my public key…