How to configure target.url in api proxy target request flow

[oyamatakuro]

Hello,

I am trying to set dynamically backend url with target.url variable.

I pick up the target URL from encrypted KVM and set the value to target.url variable with assign message policy.

But when I call the api proxy, I get the following error.

{"fault":{"faultstring":"Request path cannot be empty","detail":{"errorcode":"protocol.http.EmptyPath"}}}

I checked the variable in the trace tool, it seems that there are two target.url displayedin the "Variables" category.

One target.url vaule is the URL which I dynamically got from KVM

Another target.url is the URL I configured in the TargetEndpoint XML file

Is this the cause of the current error status?

I thought the URL in the TargetEndpoint XML would be overwritten if we set target.url dynamically in api proxy flow.

Thanks in advance.