When trying to access Admin Tools, the following error message may appear:
Ouch! More permissions are required to view this page. [Modify All Data] Please contact your administrator.
This means you need to apply for the following user permissions to:
install the app and administer an integration: Modify All Data, Manage Users, API Enabled, Apex REST Services
use airSlate custom buttons: Apex REST Services
use the airSlate Flows app: Apex REST Services, API Enabled.