I can't find a way to edit text added on a line. I can make a line/arrow I can double left-click it which adds "Text" in the middle/on my cursor. But no matter how much I double click the Text or the text area I am not able to edit the text self. If I start typing right after I double-clicked the line to add the Text nothing happens either.

I looked up and am trying to follow the line related tutorial:
But I only get this far

Interestingly enough I can use the top buttons to change the text to e.g. to italic or change font size etc. but I can't type in the field or change the actual text.

I have tried in Chrome and Microsoft Edge same result.