If you are using Okta - the wonderful people there have created this document How to Configure SAML 2.0 for Engagio. This is a great place to start. 

For everyone else, keep reading:

Step 1 - Send us your SAML metadata file from the SSO provider

We need to get the SAML Metadata file you got when you created Engagio as an SSO application. Send it over to your CSM and/or support@engagio.com

Okta - Getting the SAML Metadata file

Step 2 - Wait for us to provide confirmation that we've updated your tenant

Step 3 - Log out and log back in with SSO

For existing users who have been using passwords but want to switch to single sign-on, they should go through these steps once.

After they have completed these steps one time, in the future, the Engagio application will automatically redirect the user to their SSO provider when they want to log in.

Step 1: Log out of the Engagio web application by clicking on this link: Link to Log Out

2. On the login page, click "Not You?"

3. Enter your email address (that you use to log into Engagio) and press Submit.

4. If necessary, click "Log in with SSO Account". (Most users will not need to do this - they will be taken straight to Step 5)

5. Click "Sign on with SSO". You will be re-directed to your single sign-on provider to authenticate yourself.