1. Copy include/ocpp_configuration.def.template to your include path as ocpp_configuration.def.
2. Add or edit entries in the ocpp_configuration.def file as needed.
3. Pass in OCPP_CONFIGURATION_DEFINES=\"ocpp_configuration.def\" at compile time. Or ocpp_configuration.def.template will be used by default.
4. Then, ocpp_init().

See the examples for more details.