The "Download our SP metadata" link will only appear once the security settings are saved.
Download the SP metadata file (an xml document) and enter the appropriate settings in your IDP. In Google, this looks like the following:
This is the "Location" attribute of the <md:AssertionConsumerService> element.
This is the "entityID" attribute of the <md:EntityDescriptor> element.
Note that "Signed Response" is ticked, which corresponds to selecting Yes for "Want AuthnRequestsSigned" in step 3 above.
Note that in the Google example, "Name ID Format" is "unspecified". This could be different for your IDP and corresponds to the "NameId Format" setting in step 3 above.
iVvy should now be ready to act as the SP (service provider) and authenticate user sessions with your IDP (identity provider).
If you do not allow new users to sign up (i.e. the "Allow Signup" setting of step 3 above), you will now need to go to the Users section of your iVvy account and proceed to setup users who need access to your account.
If you do allow users to sign up (i.e. "Allow Signup" is Yes), then you can go to the login page of your iVvy account which should begin the SAML authentication process with your IDP. After successfully authenticating with your IDP, you will be presented with the following form in iVvy to complete the creation of your user profile in iVvy.