Facebook requires that you use a ‘real person’ account to manage the Facebook ads/ business manager account.
It’s this ‘real person’ account that you need to sync with WeatherAds. Once the syncing process is complete, you will then be able to toggle from your ‘real person’ account to your company profile in order to import the campaigns associated with your Facebook ads/ business manager account, into WeatherAds.
Personal Account VS. Real Person 'Manager' Account
Most marketers have a personal Facebook account (the one they use to connect with their friends outside of work) and a professional real-person account (the one they use to manage their Biz Manager/ company account). So it's about making that distinction and making sure you connect the professional real-person account, and not your away-from-work personal account (if indeed the two are separate).
WeatherAds will connect to whichever Facebook account you are currently logged in as on your browser. The easiest way to make sure you sync the correct Facebook account with WeatherAds is to first log into your Facebook ads account in your browser, and then begin the Facebook syncing process in WeatherAds.