In this blog, I am going to give some REST API endpoints to access the attachment files with its proeprties from List item:
To get all attachments from List Item:
  1. //Option 1
  2. https://<SharepointSiteURL>/_api/web/lists/getByTitle('<ListName>')/getitembyid(<ItemID>)/attachmentfiles
  4. //Option 2
  5. https://<SharepointSiteURL>/_api/web/lists/getByTitle('<ListName>')/Items(<ItemID>)/attachmentfiles
To get specific attachment based on attachment file name:
  1. //Option 1:
  2. https://SharepointSiteURL/_api/web/lists/getByTitle('<ListName>')/getitembyid(<ItemID>)/attachmentfiles('<filename.docx>')
  4. //Option 2:
  5. https://SharepointSiteURL/_api/web/lists/getByTitle('<ListName>')/getitembyid(<ItemID>)/attachmentfiles/getbyfilename('<filename.docx>')
To get the property from attachment file:
  1. https://SharepointSiteURL/_api/web/lists/getByTitle('<ListName>')/getitembyid(<ItemID>)/attachmentfiles('<filename.docx>')?$select=ServerRelativeUrl,FileName
By adding to $select=ServerRelativeUrl, FileName works for all options provided above.