Use the following URL "template" to create an SSO URL. Simply replace the phrase "Client_Custom_Domain_URL" with your custom Salesforce domain URL.

https://<<CLIENT_CUSTOM_DOMAIN_URL>>services/oauth2/authorize?response_type=code&client_id=3MVG9Y6d_Btp4xp6n5qnMzrhZgevB6QjTWHk3FIRsTElGr1efKW9J4Uqw9Q8nq6_uOA1eVgl5_ZxmwHvOgyzq&redirect_uri=https://essentials.copado.com/api/v3/users/oauthCallBack