TL;DR: there's a video at the bottom of the page
A guest account is an external access to a specific profile within your Lnk.Bio multi-account/agency panel.
Usually, guest accounts are reserved for clients of agencies who want to manage their own content independently, while the agency maintains control over the account.
Adding a guest account is very easy and only requires a few steps:
Access your Multi-account homepage
Select which of your Lnk.Bio pages you'd like to give access to, by clicking on it
From the Left Sidebar, click on the @username with the profile picture of your Lnk.Bio page, to access its settings
On the settings page, click on the Email section to add your client's email address
Now that you've set the email of your client, send them a password-reset link from the reset page using the same email you set on the settings.
Alternatively, share with them this address https://lnk.bio/reset and let them request their password when they are ready to do so.
All done! Your client can now access their single profile only, with no access to the rest of your multi-account. They can manage their Lnks, Style, etc, while you retain admin access.