Header and nested attributes?

[tsc...@pickyourplum.com]

I have a feeling there's a relatively easy solution to this but I'm having a difficult time figuring this out due to lack of available examples. Everything just seems to scratch the surface.

My WSDL: https://webservices.listrak.com/v31/IntegrationService.asmx?WSDL

From what I can tell, every request requires a UserName and Password to be included in the header, but I'm not certain how to deal with this <v31:WSUser> that comes before the UN and PW. So far I've tried a few things, including:

client = Savon.client(wsdl: "https://webservices.listrak.com/v31/IntegrationService.asmx?WSDL", soap_header: {"WSUser" => {"UserName" => "___", "Password" => "___"}, env_namespace: :soapenv})

As of right now, every request returns "Invalid Credentials" from Listrak, so I'm fairly certain my error is in the soap_header. Any suggestions or pointers in the right direction would be much appreciated. Thank you for your time!

Trevor