install agent in my locaL PC

One option is to use the AWS CLI and the S3 sync command to automatically copy files to S3. The nice thing about the sync command is that it will compute a delta since last run, meaning that any new files or updated files will be picked up instead of re-uploading every single file.

For example, if I wanted to automatically backup all of my photos from my local machine, I would run the following command:

aws s3 sync $HOME/Pictures/ s3://mybucket/Pictures/ --include "*.jpg"

The above command will "sync" my local Pictures directory into provided S3 bucket URI, and will include any files under that directory that have the .jpg filename suffix.

Then if you wanted to automate the process, you could execute the above command as a scheduled task.