Can not upload .pages files (MAC)

Hi.
I have a license to the BSK PDF Manager
I try to update .pages files but it does not upload
I can upload it in Media Manager but when clicking to attach it says “the file you selected is not supported”
I then go into BSK PDF Manager and add file type .pages
I then upload the file again.
It seems like its doing something but ends up with “missing file”
Is there an issue using “pages” files?
Thanks

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