jboss-deployment-structure.xml

<jboss-deployment-structure>
    <deployment>
        <dependencies>
            <!-- the Demo code uses classes in these modules.  These are optional to import if you are not using
                 Apache Http Client or the HttpClientBuilder that comes with the adapter core -->
            <module name="org.apache.httpcomponents"/>
            <module name="org.keycloak.keycloak-servlet-oauth-client"/>
        </dependencies>
    </deployment>
</jboss-deployment-structure>