Need to download all Attachment as per respective project

I am having one portal from where I need to download/access all attachments.
So please if there is any API/Plugin from where I can do this.

I had already performed these two below steps:
If you already have the link for your attachment for example something like
Then you can use either one of below commands to download the attachment.

curl -L -O -k -u ‘user:pass’ -X GET

wget --user=user --password=pass

In output i am getting this which is provided in attached screenshot.

I had also looked into the attachment directory where the files has stored in the server. On the attachment directory, i am getting only id[like 19123] not any attached file. Can you please suggest how can i download all attachment?
attachment directory output


This is the updated one.