dynamodb.ts

const params = {
    TableName: table,
    Key: {
        "year": year,
        "title": title
    },
    UpdateExpression: "set info.rating = :r, info.plot=:p, info.actors=:a",
    ExpressionAttributeValues: {
        ":r": 5.5,
        ":p": "Everything happens all at once.",
        ":a": ["Larry", "Moe", "Curly"]
    },
    ReturnValues: "UPDATED_NEW"
};

docClient.update(params, function (err, data) {
    if (err) {
        console.error("Unable to update item. Error JSON:", JSON.stringify(err, null, 2));
    } else {
        console.log("UpdateItem succeeded:", JSON.stringify(data, null, 2));
    }
});

error message:
Object literal may only specify known properties, and 'UpdateExpression' does not exist in type 'UpdateParam'.