Problem with SAML Request

Hi,

   When I do redirect from Sharepoint to IP-STS (SAML) to make a request I have URL like below:

https://TEST_IPSTS?wa=wsignin1.0&wtrealm=http%3a%2f%2ftest.waw.pl%2f_trust%2f&wctx=http%3a%2f%2frpsts.repozytorium.pl%2f_layouts%2f15%2fAuthenticate.aspx%3fSource%3d%252F&wreply=http%3a%2f%2f2ftest.waw.pl%2f

So I have parameters like: wa=wsigning1.0, wtrealm etc..

But from administrator of IP-STS I got information that they accept only HTTP-POST like:

·        HTTP POST/Artifact Binding

and not HTTP-GET and not QueryString.

So my question is how can I do correct request to IP-STS from Sharepoint side ?

Thanx for any help!