Allow FB access to single user in the company?

[NETWORK_USER]

Hello, I have a policy in place on my Fortigate 300c which is using default web filter and so blocking access to FB for all users. There is one user I need to open this access for. How do I implement this on the firewall? I tried creating a new policy with destination as http://www.facebook.com and made it a identity based policy. But it does not work. I do get the link to override the policy but when I click on the link it does not give me an option to enter username and password to authenticate. Is there any other simple way I can achieve this? Thank you.

[Dave_Hall]

If using FortiGuard web filtering profile, you can set the Social Network category to authenticate then choose a user/group (created prior). If you just want facebook to be override -- reclassify that site (via local ratings) as custom1 (or custom2), Then set that category to authenticate. Note that any URL filter created to block facebook will override any authentication setting you may have placed on that site via the web filtering profile. (Currently not in front of a fgt device, to confirm the exact steps -- doing it from memory.)

[NETWORK_USER]

Hello Dave, Could you please provide the procedure to set a category to authenticate? Thank you.