Fallback URL in the "Offer" column means that the traffic was redirected to a fallback (reserve) link specified in the settings.
This happens when the user does not pass the set filters e.g., specified bot filter. In such cases, the system does not send the user to the main offer, but instead redirects them to the fallback URL.
As a result, all such visits (e.g., those that triggered the bot filter) will be displayed in the statistics as Fallback URL.
