I have an api key but i'm not sure on how to make an get request using their api. The documentation is a bit vague on how to format the url, any help is appreciated!

Documentation:

https://freeserv.dukascopy.com/2.0/?path=api/currentPrices&key={api_key}&instruments=EUR/USD,USD/JPY

You can use Postman, and should see some values come back (since my key is not valid, I got 401).