curl --location 'https://tunnelsats.com/api/public/v1/subscription/create' \
--header 'Accept;' \
--header 'Content-Type: application/json' \
--data '{
"serverId": "us-east",
"duration": 1,
"referralCode": "BOOST-123"
}'{
"invoice": "lnbc30000n1p...",
"paymentHash": "a1b2c3d4e5f6...",
"amountSats": 12000,
"amountUsd": "4.00",
"expiry": "2026-09-01T20:00:00Z"
}