Cannot integrate Constant Contact with Integraly. What is Okta and how do I get an admin account?

Our team is attempting to connect a webform to constant contact. We are using the service integrately.com. While attempting to connect between integrately.com and constant contact, we receive an error regarding the redirect uri.

Integrately.com support provides instructions for this - we are told to login into okta.com. , where we can get app integration information.

We have not used this service or heard of it before. Yet, it accepts our Constant Contact login information. We are prompted to set up 2FA, which we do, are then able to login to Okta.com. However, none of the features ( such as a list of apps ) is available. We are told to contact my administrator.

How do we move forward from here?