How can you get tracing to work with zipkin in Docker?

I am trying to add tracing on a Wildfly server (specifically Keycloak Docker image)

Following this document https://docs.wildfly.org/19/Admin_Guide.html#MicroProfile_OpenTracing_SmallRye

I got as far as

embed-server --admin-only=true
/extension=org.wildfly.extension.microprofile.opentracing-smallrye:add()
/subsystem=microprofile-opentracing-smallrye:add()
/subsystem=microprofile-opentracing-smallrye/jaeger-tracer=my-tracer:add()
# /subsystem=microprofile-opentracing-smallrye/jaeger-tracer=my-tracer:write-attribute(name=sender-endpoint,value=http://tracing:9411/api/v1/spans)
/subsystem=microprofile-opentracing-smallrye/jaeger-tracer=my-tracer:write-attribute(name=sender-endpoint,value=http://tracing:9411)
/subsystem=microprofile-opentracing-smallrye/jaeger-tracer=my-tracer:write-attribute(name=propagation,value=[B3])
# /subsystem=microprofile-opentracing-smallrye/jaeger-tracer=my-tracer:write-attribute(name=tags,value=[keycloak])
/subsystem=microprofile-opentracing-smallrye/jaeger-tracer=my-tracer:write-attribute(name=reporter-log-spans,value=true)
/subsystem=microprofile-opentracing-smallrye:write-attribute(name=default-tracer,value=my-tracer)
stop-embedded-server

However, I can’t seem to get it to put anything in Zipkin server. Is it even supposed to be doing anything of the sort?

As I have noted in StackOverflow