Hello Haidar,
Welcome to the QS community!
In order to access the image from S3 in QuickSight you would need a bucket that is public. without S3 being public it wont work. If i am not mistaken QuickSight is not going to be the one accessing the image, it is the end user’s browser.
Nevertheless, you could use other site and where image is stored and can be accessible , make sure its image URL.
fore more info - see Using custom visual content - Amazon QuickSight
Hope this helps.
Cheers,
Deep