Page Designer and Attachments

While using Page Designer last week, I wanted a company logo image that would not be record-dependent but would appear on each copy of that document. I created a tab within my base specifically to store image attachments. Somehow I was able to upload the logo image and then access the resulting URL to that image and use it to achieve the desired result, but now that I’m trying to do it again with a different image I have absolutely no idea how I did it in the first place.

Now, when I right click on an uploaded image inside of an attachment field (either the original logo image or a new one) and choose to copy the record URL I get an address that terminates in locks=bipPj0VAZNA2XyfV9 (rather than the image name) and does not point to the actual image. Moreover, in spite of the fact that I have since deleted from Airtable entirely the uploaded image that I am successfully using in Page Designer, that image’s URL still pulls up the image successfully.

In short: how do you get a URL to an image you’ve uploaded as an attachment that actually brings up that image, and once you have uploaded an attachment how do you delete it permanently - such that the URL no longer access it?