Changing control font size at run time in c#

I would like to change font sizes at run time on controls such as Labels, RichTextLabels, Buttons etc in Godot 4.3 c#. Could anyone point me in the right direction?
Many thanks.

I am not a C# person, but I do know that font sizes are determined by the Theme, or in the case of Labels, by the LabelSettings. That’s a Resource which has some useful fields like the color, the font size, the actual font the use and so on.

For RichTextLabels, it might be a simple fix to use bbcode for upping the text size. Activate BBCode in the inspector and write something like this
[fontsize=50]hey hey hey![/fontsize]
It will then be displayed something like this

hey hey hey!

And that sould do the trick.