SAML ACS URL and SP Entity ID

Our IT departments wants me to put an SSO URL on a request form so our existing application can be added to our preview environment.

They say it is “the location where the SAML assertion is sent with a HTTP POST”, also referred to the SAML Assertion Consumer Service (ACS) URL. But it would seem to me that this is is an Okta URL, not something the application currently has/uses?

The other thing they are requesting is the SP Entity ID of our application. Who assigns that? Okta?

I apologize for this, but the existing application called a 3rd party’s authentication, and it is seemingly a “black box” to our application as I cannot find anything in our code other than a redirect to the 3rd party’s .dll. Our IT department is less than forthcoming about this, and the 3rd party said to contact our IT department. Classic runaround, and I’m in the middle. Thank you in advance for any information that can be provided.