This is a random bonus offered to players even without having o send money to their betting accounts. It could be either a reward for loyalty or a welcome carrot. Either way, the player gets to benefit because they can use it to play various games in the casino and get tangible wins.
Iran is known for being the successor to the Persian empire, keeping its history and traditions. Gambling in Iran is illegal and the laws are influenced by the Islamic religion. This includes online gambling. Iran has placed strict restrictions on internet usage censoring a lot of content, including foreign gambling websites.