ction hexString(buffer) {
        const byteArray = new Uint8Array(buffer)
        const hexCodes = [...byteArray].map(value => {
            return value.toString(16).padStart(2, '0')
        })

        return '0x' + hexCodes.join('')
    }

    async function fileToArrayBuffer(file) {
        return new Promise(function (resolve, reject) {
            const reader = new FileReader()
            const readFile = function (event) {
                const buffer = reader.result
                resolve(buffer