You are able to simply attach any media files as a global attachments by following the six straightforward steps that are provided below. A global attachment file will always be appended with the product attachments.
Step 1: Navigate to Media
Go to Media > Library. You will get all the files uploaded to your site and a new column named Global Attachment. This column shows the attachment status of that file.
Step 2: Find the Edit Link
Next, if you take the mouse pointer on a row, you will get the Edit option. Click on the Edit link.
Step 3: Update Attachment Status
Now, check the "Mark As Global Attachment?" box and hit the Update button.
Step 4: Check Global Attachment Status
Again, go to Media > Library. You will find the global attachment status has been changed to yes for that file.
Step 5: Enable Global Attachment Option
Now, navigate to the "Woo Attachment > Option Panel > Advanced Options" page. Next, turn "ON" the option Enable Global Attachment? and click the Save Changes button.
Step 6: Global Attachments Results
Finally, go to any WooCommerce product page, and you will get an output like the following screenshot: