jboss-deployment-structure.xml.wildfly

<jboss-deployment-structure>
    <deployment>
        <dependencies>
            <!-- The keycloak-undertow-adapter is required -->
            <module name="org.keycloak.keycloak-undertow-adapter" services="import"/>
            <!-- 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-adapter-core"/>
        </dependencies>
    </deployment>
</jboss-deployment-structure>