SAML single sign-on for on-premises applications with Application Proxy

Hi All,

I am trying to achieve the Sp Initiated flow SAML based with Cookies enabled Azure App Proxy authentication.

Refrence URL -  https://docs.microsoft.com/en-us/azure/active-directory/manage-apps/application-proxy-configure-single-sign-on-on-premises-apps


My Proxy URL something like ,  xxx.msappproxy.net. Once access the Proxy URL , it will redirected to the Azure AD login after once successfully login then it will come back to the my Angular + Node JS UI Application with the below App Proxy Cookies 

Name                                                                           Value

AzureAppProxyAccessCookie_XXXX_1.3                  3|XXXXX

AzureAppProxyUserSessionCookie_XX_1.3              3|XXXXX

AzureAppProxyAnalyticCookie_XXX_1.3                   3|XXXXX
As per the Sp Initiated flow.I need to submit SAML request to AD to get SAML response from AD to validate the User and get the access token to make another call using Microsoft Graph API to get the members details.

I am not sure , how to proceed from this to form or submit the SAML request. What kind of information available in the App Proxy Cookie. Please help.

Thanks in Advance.