Doesn’t work with PayPal Express Checkout

Hello! I have purchased premium version of this plugin and sadly I cannot use it still…
When it’s enabled and someone tries to purchase while using PayPal Express Checkout button, the price doesn’t convert to USD (only currency that I allow for check out with PayPal). I’ll give you an example.
Price of the product is $108, but the customer selected currency SEK.
When he chooses PayPal Express Checkout, the final price is somehow SEK 108, instead of $108.
I really need to fix this please. thank you!