You may have been notified of an invitation to a new project on GoContractor. In some cases, this is by an Invitation code.
If your employer or GoContractor administrator has created a unique code to invite you to a project listed on GoContractor. They should have provided you with this code in some way.
If not, you will need to reach back out to them to provide you with this code OR they can invite you directly by email . GoContractor does not provide invitation codes as this must come from an administrator.