About the Salesforce Integration User
You need to create an integration user account in Salesforce which will be the dedicated account to use Salesforce Connector. The Salesforce integration can be a Salesforce system administrator or a minimum access API-only integration user.
Important:
You need to enable OAuth Username-Password Flows in Salesforce. To do so, log in to Salesforce as an administrator and enable Allow OAuth Username-Password Flows by clicking the gear icon (Setup) > Identity > OAuth and OpenID Connect Settings.
If you create an API-only integration user, you need to enable Administrators Can Log in as Any User in Setup > Users > Login Access Policies in Salesforce.