These live in Client Config > Marketing: Social (not on the Integrations page itself). Paste the full profile URL into any of Facebook, Twitter, Youtube, Instagram, Yelp, TikTok or Whatsapp phone number; leaving a field blank hides that icon in the website footer, and a filled-in one opens the link in a new tab there.

System emails have their own, simpler icon row in the footer, covering only Facebook, Instagram, Twitter, Yelp and TikTok (no Youtube or Whatsapp icon). That row is not conditional the way the website footer is - it always shows all five icons regardless of whether you filled in a link, and clicking one doesn't open a new tab, so an empty field there just leaves that icon pointing nowhere useful instead of disappearing.

These are simple link fields, separate from the Yelp Reviews integration card (which pulls your actual reviews onto a page) and from the reCAPTCHA/Klaviyo-style cards - there is no verification step, they just need a valid URL.