A "restricted" message when linking your Instagram and Facebook Page is almost always an error on Meta's side, not an issue with Scaled Creator.
What usually clears it?
The restriction often lifts on its own after a couple of days, so waiting and trying again is worth doing first.
In the meantime, you can take these steps.
Enable two-factor authentication on the account.
Change the password to something strong.
Try linking again in an incognito or private browser window.
What if the restriction doesn't go away?
If it persists, open a support ticket with Meta if that option is available to you. Meta's support chat is usually only offered to verified accounts.
This one sits entirely on Meta's end, so there's nothing to change inside Scaled Creator to fix it.