Given you are able to successfully upload the file using Postman you can just record the associated request using JMeter.

1. Prepare JMeter for recording. The fastest and the easiest way is using JMeter Templates feature. From JMeter's main menu choose File - Templates - Recording and click "Create

   

2. Expand Workbench - HTTP(S) Test Script Recorder and click "Start" button

   

3. Run Postman using JMeter as proxy server like:

   C:\Users\Jayashree\AppData\Local\Postman\app-4.9.3\Postman.exe --proxy-server=localhost:8888
   

4. Put the file you need to upload to the "bin" folder of your JMeter installation
5. Run the request in Postman - JMeter should record it under Test Plan - Thread Group - Recording Controller

See HTTP(S) Test Script Recorder documentation for more information.

Have you properly specified the AWS credentials in the JMeter PUT request ? You need to specify AWS Access Key and secret key.

Another solution would be to use the AWS Java SDK from a JSR223 sampler, and make the call using Java code.

I have mentioned the steps to upload an image to s3 bucket using JMeter below:

Requirements:

• Java 9
• aws-java-sdk-s3 JAR 1.11.313 dependencies link

Steps:

• Copy the jar files to JMeterHome/lib/ext/ of Jmeter.

• Create a Test Plan and click on Thread Group.

• Set Number of Threads, Ramp-up period and Loop Count to 1.

• Right click on thread groups and add a JSR233 sampler.

• Select Java as the language in the JSR233 sampler.

• Add the following code in the script section of the sampler.

   import java.io.IOException;
   import java.io.InputStream;
   import java.util.Properties;
   import java.util.ArrayList;
   import java.util.List;
   import java.util.Scanner;
   import com.amazonaws.auth.AWSSessionCredentials;
   import com.amazonaws.auth.AWSStaticCredentialsProvider;
   import com.amazonaws.auth.BasicAWSCredentials;
   import com.amazonaws.services.s3.AmazonS3;
   import com.amazonaws.services.s3.AmazonS3ClientBuilder;
   import com.amazonaws.services.s3.model.AmazonS3Exception;
   import com.amazonaws.services.s3.model.GetObjectRequest;
   import com.amazonaws.services.s3.model.PutObjectRequest;
   import com.amazonaws.services.s3.model.PutObjectResult;
   import com.amazonaws.services.s3.model.S3Object;
   import com.amazonaws.services.s3.model.S3ObjectInputStream;
   import com.amazonaws.regions.Regions;
   import com.amazonaws.regions.Region;
   import com.amazonaws.services.s3.model.ObjectMetadata;
   import com.amazonaws.services.s3.transfer.Download;
   import com.amazonaws.services.s3.transfer.TransferManager;
   import com.amazonaws.services.s3.transfer.TransferManagerBuilder;
   import com.amazonaws.services.s3.transfer.Upload;
  
   String accessKey = "xxxxxxx";
   String secretKey = "xxxxxxxxx";               
   String bucketName = "bucketname"; //specify bucketname
   String region = "region"; //specify region
  
   BasicAWSCredentials sessionCredentials = new BasicAWSCredentials(accessKey, secretKey);
  
   AmazonS3 s3 = AmazonS3ClientBuilder.standard()
  .withRegion(region)
  .withCredentials(new AWSStaticCredentialsProvider(sessionCredentials))
  .build();
  
   TransferManager xfer_mgr = TransferManagerBuilder.standard()
  .withS3Client(s3)
              .withDisableParallelDownloads(false)
              .build();
  
   File f = new File("xxx/image.jpg"); //specify path to your image 
   String objectName = "newimage.jpg"; //provide a name for the image how you want your image to be shown i
   Upload xfer = xfer_mgr.upload(bucketName, objectName, f);   
   xfer.waitForCompletion();  
   xfer_mgr.shutdownNow();
  

For more reference you may check this link