APM Single Sign On (SSO) with HTTP form use "multipart/form-data"

Hi Pros

I'm config APM SSO to the Web Application with HTTP form. But the login page use "multipart/form-data". The Username & Password parameters in the POST request as this:

    ------WebKitFormBoundaryjMJPcAP9XlfsAQ7L
Content-Disposition: form-data; name="dnn$ctr$Login$Login_DNN$txtUsername"

usernameherre
------WebKitFormBoundaryjMJPcAP9XlfsAQ7L
Content-Disposition: form-data; name="dnn$ctr$Login$Login_DNN$txtPassword"

passwordhere
------WebKitFormBoundaryjMJPcAP9XlfsAQ7L
Content-Disposition: form-data; name="dnn$ctr$Login$Login_DNN$cmdLogin"

How can I configure SSO HTTP Form?

Phong