Kate how to add automatic file extension .txt

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1

Is it possible to add a default “.txt” file extension in Kate. I’m using version 23.08.5.
If I change the input mode via Tools > Mode > Markdown then “.md” isn’t added when I save a new file either.
Is this caused by the “Automatically select filename extension” checkbox being disabled in the Save File dialog?

save file dialog
save file dialog884×353 32.2 KB

If you know how to change the default text input mode to Markup/Markdown that would be great too.

Thanks for your help. :smiley: