SizeProp is available to residents of most countries worldwide, that being said there is a list of restricted countries:
Restricted countries and regions:
United Arab Emirates, Afghanistan, Belarus, Myanmar, Cambodia, Central African Republic, China, Cuba, Democratic Republic of the Congo, Ethiopia, Eritrea, Haiti, Iran, Iraq, Lebanon, Libya, Nicaragua, North Korea, Russia, Somalia, South Sudan, Sudan, Syria, Venezuela, Vietnam, Yemen, Zimbabwe, and the Ukrainian regions of Crimea, Donetsk, and Luhansk.
Using a VPN or other methods to bypass these restrictions is prohibited and will result in account termination and forfeiture of any pending payouts.