How to reduce runtime for Lambda function that reads JSON and puts data in DynamoDB

My Lambda function does a get request to a JSON api and puts the data in DynamoDB. However, it takes way too long run, because the JSON is quite large. How can I adjust my code so that my runtime reduces? Or can I adjust my DynamoDB settings to make the write process work faster?

exports.handler = async (event) => {
    try {
        const data = await httprequest();

         for (var i = 0; i < data.d.results.length; i++){
         var iden = Date.now();
        var identifier = iden.toString();

            var params = {
            Item: {
                ID: identifier,           
                journal: data.d.results[i].journal
            },

            TableName: ''test"
        };

        await docClient.put(params).promise();

        }


        console.log('Document inserted.');

        return JSON.stringify(data);
    } catch(err) {
        console.log(err);

        return err;
    }
};