Cognito as service provider force http-post redirect

Hi,

Currently, my team tried to implement a SAML authentication between cognito as sp for our application and corp idp, where we don't have any details about solution used. We have an error displayed:

• Required String parameter 'RelayState' is not present

And corp team tell us to control that we sent this parameter, however when I click on Host-UI url i don't see this. Another thing I see that most of their application enrolled in SAML authentication use http-post redriect, however our cognito use each time http-get redirect url. Is it a way to force post instead of get ?

Best regards,