The ability to choose the SAML response signature is available for custom service providers (SP) only.
This option is available for service providers that require the SAML Response to be signed instead of signing the SAML Assertion inside the SAML Response.
The Sign Assertion option is selected by default. You can select the Sign Response option if appropriate.
SAML Responses received by Ivanti Access must always have the Assertion signed. However, the Response must not be signed.