Hello there, Laurita. It's my pleasure to help with the issue with the invitation link.
Sometimes, the "Access Denied" error occurs if the invited user takes too long to access the invitation link. The invitation link expires if not used within a specified time.
To resolve this, we can resend the invitation and ask the user to access the link immediately upon receipt. Delays in accessing the invitation are a common reason for the rejection message.
If the problem persists, ask the user to accept the invite using a private (incognito) browser window or switch to another supported browser, as this can enhance functionality and avoid any cached data or login issues.
Feel free to add your response in the Comment section below, Laurita.