I must have been to that site over 100 times and still can’t seem to get the offer. I had the same offer that expired September 30, but no luck as of now.
Updated (thanks to @currybob) with the link to registration:
https://f150inyourdriveway.com/registration/
Just got an email to test drive the 2021 F-150 here in the Atlanta area next month. In the invite, there were 4 cities to choose from, Atlanta, Dallas, Miami and Orlando. Cant wait :)