If Tot is not open, the append to Tot extension only opens the app but doesn’t append the text to the note.
Thanks. Pretty sure this one needs to be reported to Tot developer (I cant remember their name!), since the extension only calls Tot’s own built in URL scheme.
I suppose as a workaround the extension could use AppleScript check to see if Tot is running, launch it and await finishing launching, and only then call the URL scheme (and I will leave this as an exercise to the reader, a robust working & tested pull-request will be gladly accepted) — but it would be better fixed at the source.