I was curious to understand this issue, although I have never used paypal for online gambling.
I have found that it can be used without problems in countries and states where gambling is allowed. Such countries and states include: UK, Austria, Belgium, Denmark, Finland, France, Greece, Ireland, Italy, Portugal, Spain and Sweden. There are three states in the United States where you can use PayPal: New Jersey, Nevada and Delaware.
In all other cases, I recommend trying other methods that are relevant to America. These are the following options:
Credit, debit, gift or prepaid cards
Bitcoin
Money transfer services (such as Western Union)
I used everything except bitcoin, it's a pretty easy process. I think you will understand or find the information yourself.
Good luck to all!