Technically, every person in the world have cellular phone (many people have more than one).
So you just need to rent 8b lines in call centers, and make site with 2fa auth with voice recognition, and call all people at once, so nobody could use 2 phones simultaneous.
Second, in every country now possible to go to nearest bank (may be abroad), and there got their dollar, if tell secret code (there are lot of payment systems working such way, or you could create your own for some territories).
Also or for some cases, you could just send to each verified phone sms with money code, for example some crypto, like btc.
That's all, may be you will spend few b for call centers and for payment systems fees, and to establish your own payment systems for some cases.
Children in most countries are not allowed to deal with strangers, only adults allowed, so you could not send money to children directly.
PS North Korea in reality is proxy country, most their citizens are allowed to go to fulltime work to China.
So you just need to rent 8b lines in call centers, and make site with 2fa auth with voice recognition, and call all people at once, so nobody could use 2 phones simultaneous.
Second, in every country now possible to go to nearest bank (may be abroad), and there got their dollar, if tell secret code (there are lot of payment systems working such way, or you could create your own for some territories).
Also or for some cases, you could just send to each verified phone sms with money code, for example some crypto, like btc.
That's all, may be you will spend few b for call centers and for payment systems fees, and to establish your own payment systems for some cases.
Children in most countries are not allowed to deal with strangers, only adults allowed, so you could not send money to children directly.
PS North Korea in reality is proxy country, most their citizens are allowed to go to fulltime work to China.