I'm trying to import this example into postman
curl -s --user 'api:YOUR_API_KEY' \
https://api.mailgun.net/v3/YOUR_DOMAIN_NAME/messages \
-F from='Excited User <mailgun@YOUR_DOMAIN_NAME>' \
-F to=YOU@YOUR_DOMAIN_NAME \
-F to=bar@example.com \
-F subject='Hello' \
-F text='Testing some Mailgun awesomness!'
Please help me understand the -s, --user, -F, what is that? And then when I try to import, I get this error: option-less arguments found. How can I fix this?