OptusSiteAdapter is hard-coded in core spring xml configuration

backend/services/core-site-parent/core-site-service/src/main/resources/smb-site-service-spring.xml

<!-- Site Adapter -->
<bean id="SiteAdapter" class="com.thesearchagency.smb.service.site.adapter.OptusSiteAdapter"/>

Example of how to fix using runtime variable substitution with properties file and environment-specific profile setting:
backend/services/core-callback-parent/core-callback-service/src/main/resources/smb-callback-service-spring.xml
backend/services/core-callback-parent/core-callback-service/src/main/resources/smb-callback-service.properties
backend/services/core-callback-parent/core-callback-service/pom.xml

To verify, the AdMaxLocal site service and Optus site service should both be tested.