8 files declare their use of JsonapiResourceConfig in JSON:API Extras 8.3

ConfigurableResourceType.php in src/ResourceType/ConfigurableResourceType.php

EntityResource.php in modules/jsonapi_defaults/src/Controller/EntityResource.php

JsonApiBuildSubscriber.php in src/EventSubscriber/JsonApiBuildSubscriber.php

JsonApiDefaultsFunctionalTest.php in modules/jsonapi_defaults/tests/src/Functional/JsonApiDefaultsFunctionalTest.php

JsonApiExtrasFunctionalTest.php in tests/src/Functional/JsonApiExtrasFunctionalTest.php

JsonapiResourceConfigForm.php in src/Form/JsonapiResourceConfigForm.php

jsonapi_defaults.module in modules/jsonapi_defaults/jsonapi_defaults.module

Contains module related hooks.

NullJsonapiResourceConfig.php in src/ResourceType/NullJsonapiResourceConfig.php