Lines joined with fillet or radius

Is there a way to easily modify the way two lines join so that instead of a simple line to line junction, they join with a specified radius, or a fillet, as in my sketch? Or is there an extension that will do this?
(I haven’t used the extension warehouse much, but didn’t really know how to find something like this…?!)!
Screenshot 2020-05-31 at 09.32.57|690x260

1001bit-tools plugin

Use Search after what you need, in this case… ‘fillet’.

Perfect thank you!!

You could also use my old plugin BezierSpline

…or the newer version FredoSpline, which offers settings for individual corners (style, radius, number of segments).