Unable to add my account as a sub-user of another account

Hello, I have been invited to be a sub-user under my employer - Larimer County, and have been instructed to only use jotforms under this sub-user method, however when I click on the link to become a sub-user, the jotforms page I am taken to is the one for my own account. 

Since you already have an account with us, please ask your employer to send you the invitation using your username: AmyGuy this should add you as a sub-user to that account and you'll receive an email confirmation when the access is granted.

Let us know if this helps.
Thanks.