Athena UDF lambda, An error occurred during JSON parsing

I create lambda function to be used in athena UDF.

USING EXTERNAL FUNCTION decrypt(variable1 VARBINARY)
RETURNS VARCHAR
LAMBDA 'LambdaFunctionName'
SELECT  decrypt(amount) FROM "database"."table_name" limit 10;

but it give error

GENERIC_USER_ERROR: io.trino.spi.TrinoException: Encountered an exception[java.lang.RuntimeException] from your LambdaFunction[LambdaFunctionName] executed in context[ping] with message[An error occurred during JSON parsing]

my lambda function using java code, the class extend UserDefinedFunctionHandler and the code something like this

 public String decrypt(String input) {
        byte[] valueByte = input.getBytes();
        String result = decryptByte(valueByte);
        return result;
    }

even when i change VARBINARY to VARCHAR, and change the query parameter to some string like SELECT decrypt('somestring') it still give the same JSON parsing error