curl --request POST \
--url https://mainnet.gomaestro-api.org/v1/contracts/subscription/createUserAccount \
--header 'Content-Type: application/json' \
--header 'api-key: <api-key>' \
--data '{
"subscriber_address": "<string>",
"selected_out_ref": {
"tx_hash": "<string>",
"output_index": 123
},
"email": "<string>",
"phone": "<string>"
}'