Some documents, like the Presentence Report, do not have PageID#s. Others, like sealed documents and transcripts, might not have accessible PageID#s at the time you file your brief. Per Cheryl Borkowski at the Sixth Circuit, if you don't have it and/or cannot get it, just don't put one in. The judges will not reject your brief.
As a personal practice, I think I'll be dropping a footnote at first reference to a transcript, to remind judges that I do not have access to the docketed transcript until well after I submit my brief.