Please logout of all Google accounts and login only with one Google account where you installed FileDrop add-on.
Alternatively use an incognito or private browser window.
Google Workspace administrators can manage blocked third-party apps by navigating to
Security > Access and data control > API controls > Manage Third-Party App Access in the Admin console.
This section allows viewing, filtering, and changing access levels (Trusted, Limited, Blocked) for apps attempting to access Google data.