I have been running Gambling Ads for years.
Id imagine you want to run as an aggregator ( Affiliate ) not as Operator.
Each country is regulated differently from Google Policy point of view, and google would not allow you to run ads in some countries ( despite online gambling being legal in these countries ).
If you want to advertise As an operator you need to submit your licence to google
As an affiliate, in most countries, you do not need a licence but still must comply with google rules and cannot send your ads to an operaotr page, but must build a list of operators with their offers. all operators you list MUST have a legal licence to operate in that specific country
In some countries google would allow operators only to advertise
If you want to advertise in countries where google do not allow online gambling ads, then you have to use alternative techniques: cloaking, VPS and old aged accounts. a little more complicated, but possible
let me know if I can be of further help