I'm in the process of setting up a new LinkedIn Post Brand Mentions signal, but I don't see an option to link the brand account. I'm pretty sure it used to be there.
For LinkedIn brand mentions signals, you need to provide your LinkedIn organization ID rather than linking a brand account directly.
You can add this in two ways:
** Enter your LinkedIn organization ID directly (e.g., 13018048)
** Paste your LinkedIn admin URL (e.g., https://www.linkedin.com/company/13018048/admin/dashboard/)
The setup process asks for your "organization identifier" instead of account linking.