B2B Addon AS2 payload content-type

Hi,

SAP PI 7.3.1 with B2B Addon.

I am trying to configure a SOAP to AS2 scenario. AS2 receiver is web methods. I am using ASC810_004010.

I have the following questions

Webmethods is expecting text payload starts with ISA* but SAP PI is sending the payload in XML. How to resolve this and where?

Please provide pointers.

Thanks,

Karthik