요청 정보 = {"refSellerId":"my-seller-1","businessType":"INDIVIDUAL_BUSINESS","company":{"name":"테스트 상호","representativeName":"김토스","businessRegistrationNumber":"1234567890","email":"toss@sample.com","phone":"01012345678"},"account":{"bankCode":"020","accountNumber":"12001123866091","holderName":"김토스"}}