Lookalike audience country - Enter the country of residence for audience members whom you want to target because they resemble individuals whom you already target. Facebook Ads lookalike audiences must be specific to a single country. For more information, refer to the Facebook Ads documentation.

Lookalike audience ratio - Enter the percentage of the population of the lookalike audience country whom you want to target. For example, a lookalike audience ratio of 0.01 targets 1% of the population of the selected country. Larger audience ratios target more people, but the targeted audience members may have less resemblance to individuals whom you already target. For more information, refer to the Facebook Ads documentation.