Does not work with Firefox 88

[ndias]

I have this error in the console

stderr output from native app signtextjs_plus: Could not detect profile directory
SignText: Native back end disconnected common.js:15:11

This happens in Fedora 33 with firefox-88.0-4.fc33.x86_64

[jasp00]

The add-on works with Firefox 91.4.1 ESR on Debian Linux.