PayPal Smart Payments: changing the currency code - paypal

Question

I'm trying to set up PayPal Smart Payments on a webpage. I'm using the example they give on here: https://developer.paypal.com/docs/checkout/integrate/
If I have currency_code set to USD it works fine, but if I change it to anything else, such as CAD or GBP the window won't load. What am I doing wrong?
<script src="https://www.paypal.com/sdk/js?client-id=sb"></script>
<script>
paypal.Buttons({
createOrder: function(data, actions) {
return actions.order.create({
'purchase_units': [{
'amount': {
'currency_code': 'USD',
'value': '5',
},
}]
})
}
}).render('body')
</script>
For some reason this example won't run here on Stack Overflow, but it runs fine on JSFiddle, so I have made two examples with the currency_code set differently.
'currency_code': 'USD': https://jsfiddle.net/liquidmetalrob/8y3p52fh/
'currency_code': 'GBP': https://jsfiddle.net/liquidmetalrob/8y3p52fh/1
The first example will load the PayPal window, and you need a PayPal Sandbox account to log into it. So if you want to log in you can use the throwaway account that I just created. Username: sb-ilukn1050819#personal.example.com password: pRKCu9.> But the important question is why does the window not even load in the second example?

Answer 1

I found the answer here: https://developer.paypal.com/docs/checkout/reference/customize-sdk/
You have to add the currency code to the script URL instead, and remove it from the JS.
<script
src="https://www.paypal.com/sdk/js?client-id=sb&currency=GBP">
</script>
<script>
paypal.Buttons({
createOrder: function(data, actions) {
return actions.order.create({
'purchase_units': [{
'amount': {
'value': '5',
},
}]
})
}
}).render('body')
</script>
Note: The client-id can be set to sb for testing, but in production you use your own one.