fromBase64
Create binary data from a Base64-encoded string. See Chapter 38.
encoded(required): Base64-encoded string
bash
echo '{"data": "SGVsbG8gV29ybGQ="}' | utlx -e 'toString(fromBase64($input.data))'
# "Hello World"utlx
{
decoded: toString(fromBase64($input.encodedPayload))
}