How can I set the property value using SpEL in the XML file?

Question

I want to set the property named "uriVariablesExpression" as a value of Map type. It will be run as a service activator in a integration flow. And the input channel will have a message that payload has the value of Map type. How can I set the property using SpEL?

I already saw the article about it. but it didn't help for me.

<bean id="gitlab-http-outbound-bean"
      class="org.springframework.integration.http.outbound.HttpRequestExecutingMessageHandler">
      <constructor-arg value="http://70.121.224.25/gitlab/api/v3{gitlab.data.type}{gitlab.private.token}" />
      <property name="uriVariablesExpression" value="payload"/>
      <property name="outputChannel" ref="redca-normalized-channel" />
    </bean>