Hi @BollGary,
Do you want to collect all the attachments names?
Do you want to pull the SP List attachments into a collection using the ClearCollect function?
I have made a test on my side, if you want to pull the SP List attachments into a collection using the ClearCollect function, I afraid that there is no way to achieve your needs within PowerApps currently.
Currently, we could only access the SP List item attachments within the Attachments control of a Edit form. More details about the Attachments control within PowerApps, please check the following article:
Attachments control
As a workaround, you could try to add a Gallery and populate it with your SortByColumns() formula so that you could create a collection by all the items from the Gallery, where stores the attachments display name.