I'm here to help you with accepting the contractor's invitation for W-9, William.
To narrow down the result, you can start by asking your employer to send the invitation again. From there, open your email and access the link through a private window. Alternatively, you can access the invitation through a supported web browser. Once you've opened the link successfully, you can proceed with these steps:
If you already have a QuickBooks Self-Employed account, select Sign in. If not, follow the steps to create a limited QuickBooks Self-Employed account. This account has limited features: you can fill out your W-9, submit it, and view your 1099-MISC.