Upgrade to IOS 15, IPAD endnote no longer has keyboard pop-out

I recently upgraded my IPAD pro to IOS 15 and I found out that IPAD Endnote no longer has pop-out keyboard  on screen, nor can I use my external keyboard to type anything.  The touch screen function is okay.  However, when i tried to edit references or write on notes, keyboard function is completey disappearing.

I don’t think it is a bug for IOS 15 because other APPs work fine.  I am using my external keyboard to type this letter right now using my ipad.  It must be endnote Ipad version incompatible with the new IOS.

What can I do?  I often download pdfs to ipad endnote and later manually edit references information.   Without keyboard function, endnote IPAD app is useless for me.