Organic Way
1. Use Static Residential Proxy and Anti Detect Browser to create FB account. Keep your expected country when using IP. Then FB will suggest you only FB groups from this country. Then warm up your account, and promote like HUMAN, not like MARKETER.
2. Find if your targeted country have any local social media, such as, NextDoor is a local social media of USA only. So, if you can create account on NextDoor somehow, you will get a lot of US traffic if you can promote your link here. Similarly, find you targeted country's local social media.
Paid Way
1. Research about push , native, pop under, etc ads and TEST TEST TEST.