'Copy Link' and 'Share' create unique permission automatically

johnjohn-Peter I don't think you will be able to change the SharePoint default functionality of "Copy link" option in the document library.

If you want a direct link to SharePoint file to share with users who are already having permissions on the file, follow below steps to get the file URL:

1. Go to the document library/folder where your file is uploaded.
2. Select the file and click on Open the details pane ( i icon) from command bar (top right side)
3. Copy direct link using the copy icon highlighted in below image: 

You may need to append ?Web=1 to open file in web browser before sharing it with other users, like (only if when you open the copied link in browser and it is downloading the file instead of opening in the browser): 

https://contoso.sharepoint.com/sites/MySite/MyLibrary/MyDocument.docx?Web=1

Additionally, you can hide the "Copy link" option from library command bar using SharePoint JSON view formatting: 

{
  "commandBarProps": {
    "commands": [
      {
        "key": "copyLink",
        "hide": true
      }
    ]
  }
}

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