curl --location --request POST 'https://open.ocrmath.com/v2/account/get_usage' \ --header 'x-api-key;' \ --header 'x-md5;' \ --header 'timestamp;' \ --form 'date="2020-10-01"'
{ "errno": 201, "data": { "date": "2020-10-01", "usage": 3 } }