curl --location 'https://api.vietqr.org/vqr/api/transaction/refund' \
--header 'Cookie: JSESSIONID=5CAD2D74C5EBDF9B1CAC5684F2DB47CE; JSESSIONID=C1711954475F66AE09967ADFFA4C80CD; JSESSIONID=F40E5CBDEEB02F82DF40BAD476A6222B' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer eyJhbGciOiJIUzUxMiJ9.eyJhdXRob3JpdGllcyI6WyJST0xFX1VTRVIiXSwidXNlciI6IlkzVnpkRzl0WlhJdGJtZDFlV1Z1TFhWelpYSXlORGt5IiwiaWF0IjoxNzIxMjk3NjAxLCJleHAiOjE3MjEyOTc5MDF9.SEy2kqjhNup2UVaKhldXZQ1bVJn6o69LxgF9r0yA7zBqJWC5n9PhFUYk3G_oBsmCrAbobMohNHzJRsgqbwsUUA' \
--data '{
"bankCode": "mã_ngân_hàng",
"bankAccount": "tài_khoản_ngân_hàng_đồng_bộ",
"referenceNumber": "mã_giao_dịch_đã_thanh_toán_cần_hoàn_tiền",
"amount": "số_tiền_được_hoàn",
"content": "nội_dung_hoàn_tiền",
"multiTimes": "true: cho_phép_hoàn_tiền_nhiều_lần",
"terminalCode": "mã_điểm_bán",
"subTerminalCode": "mã_con_điểm_bán",
"checkSum": "HASH MD5 128 bit: secret_key_do_vietqr_cung_cấp + referenceNumber + amount + bankAccount"
}'