An OCPP server (Open Charge Point Protocol server), also known as a CPMS (Charge Point Management System) or CSMS (Charging Station Management System), is a central software system that manages and communicates with electric vehicle (EV) charging stations, known as charge points or EVSEs (Electric Vehicle Supply Equipment). It uses the OCPP standard, which is an open, standardized protocol for communication between charging stations and management systems.
Within the OCPP specification documents, chargers connecting to a CPMS using either SecurityProfile 1 or 2 must connect using Basic Authentication. In the real world, many charger manufacturers allow you to configure basic authentication credentials regardless of whether or not the SecurityProfile of the chargepoint has been specified.
The access credentials, in this case a username and password, are taken from the chargePointId (which becomes the username) and the configuration key "AuthorizationKey" (which becomes the password).
OCPP websocket communications can be established via unsecure or secured connections using TLS. It is strongly recommended to always TLS for these sockets, as it greatly increases security and significantly reduces the risks of malicious parties snooping on your communications. Technically this is supported in OCPP1.6 Security Whitepaper or OCPP2.0.1 via the SecurityProfile configuration setting, but most chargepoints handle TLS connections without any SecurityProfile being specified.