There’s no college-wide or university-wide licensing with FlipGrid, or accounts for that, but FlipGrid is owned by Microsoft, so sign up with your Drexel account and it seems to just let you use it as a Instructor if you do so.
There are free educator accounts available to you if you use the “Sign up with Microsoft” and enter your Drexel usrerid (for example: firstname.lastname@example.org ).
Here’s the “Getting Started: Educators” webpage.
Here’s the “Getting Started: Students” webpage.
Create a Group in FlipGrid.
More “Getting Started” help.
What is FlipGrid article from Tech Learning