This example will use the base title defined in $:/language/DefaultNewTiddlerTitle.

It will overwrite the tiddler, if the button is clicked several times.

\define testCreate()
<$action-createtiddler $basetitle={{$:/language/DefaultNewTiddlerTitle}} $overwrite="yes"/>
\end

<$button actions=<<testCreate>> >
Create Tiddler
</$button>

Create Tiddler - Clicking this button, will also open the Right sidebar: Recent tab