[bug] Can't set enty syncing off or delete a entry

[ameaninglessname]

Describe the bug
It seems that I'v synced too much stuff that my cloud storage has hit the limit.
I want to disable Firefox sync and do it myself.
But now I can't delete those synced entry to release some space for cloud storage.

To Reproduce
---NONE

Expected behavior
Find some way to delete synced entry

Screenshots

Which OS, Firefox edition, Textmarker version
TextMarker 5.3.1
Firefox 91.0.1
Windwos 10 21H1 19043.1165

*Awesome extension, many thanks to @ufb ❤