- Once you've created a new app using the template, you'll be prompted to create a **new version** of the existing version. After creating a new version, you'll be able to make changes in the app.
<imgstyle={{border:'0',marginBottom:'15px',borderRadius:'5px',boxShadow:'0px1px3pxrgba(0,0,0,0.2)'}}className="screenshot-full"src="/img/how-to/uses3presignedurl/newversion.png"alt="Use S3 pre-signed URL to upload documents: new version"/>
- Go to the **datasource manager** on the left-sidebar, you'll find that the **AWS S3 datasource** is already added. All you need to do is update the datasource **credentials**.
:::tip
Check the [AWS S3 datasource reference](/docs/data-sources/s3) to learn more about connnection and choosing your preferred authentication method.
- Once the datasource is connected successfully, go to the query manager and **Run** the **getBuckets** query. The operation selected in the getBuckets query is **List Buckets** which will fetch an array of all the buckets.
- Select a **bucket** from the dropdown and click on the **Fetch files** button to list all the files from the selected bucket on the table. The **Fetch files** button has the event handler added that triggers the **s32** query, the **s32** query uses the **List objects in a bucket** operation, and the bucket field in the query gets the value dynamically from the dropdown.
<imgstyle={{border:'0',marginBottom:'15px',borderRadius:'5px',boxShadow:'0px1px3pxrgba(0,0,0,0.2)'}}className="screenshot-full"src="/img/how-to/uses3presignedurl/fetchfiles.png"alt="Use S3 pre-signed URL to upload documents: list objects in a bucket"/>
- Create a **runjs1** query and copy-paste the code below. This query gets the **base64data** from the file picker and convert the file's `base64Data` to into `BLOB`, and returns the file object.
- Create another **runjs2** query and copy-paste the code below. This query gets the data(file object) returned by the first runjs query, the url returned by the **uploadToS3** query, and then makes PUT request.
- For the file to be uploaded successfully, you will need to add the CORS policies from the **Permissions** tab of your **Bucket** settings. Here's a sample CORS:
- Go to the **uploadToS3**, scroll down and add an event handler to the **uploadToS3** query. Select the **Query Success** event, **Run Query** as the action, and **runjs1** as the query to be triggered. **Save** the query.
- Let's go to the **runjs1** query and add the event handler to run a query on query success event, similar to how we did in the previous step. In the event handler, choose **runjs2** query. **Save** the query.
- Now, let's go the final query **copySignedURL** that is connected to the table's action button. This query copy's the generated **Signed URL for download** onto the **clipboard**.
- Now that we have updated all the queries, and connected them through the event handlers. We can go ahead and pick a file from the file picker. Click on the file picker, select a file and then hit the **Upload file to S3** button.
- Once the button is clicked, the **uploadToS3** will triggered along with the **runjs1** and **runjs2** queries in sequence since we added them in the event handlers.
- You can go to the table and click on the **Copy signed URL** action button on the table, this will trigger the **copySignedURL** query and will copy the URL on the clipboard. You can go to another tab and paste the URL to open the file on the browser.
