Postman has been an indispensable tool I have been using for doing one off testing on the SaaS API I have been developing side benefits it provides are conversion to cURL statements and synchronization of saved requests when you create an account and login.

Example API call

Then press Code and select cURL, there are a myriad of options available, but cURL can be easily installed on most any computer easily enough

curl -X GET \
  'https://api.solcast.com.au/radiation/forecasts?api_key=<API_KEY>&longitude=-0.076132&latitude=51.508530' \
  -H 'Content-Type: application/json' \
  -H 'cache-control: no-cache'