Set new dash or dot style

[drcsturm]

Could someone please show me how to create a new dash style?
My MWE does not work:

\documentclass{article}

\usepackage{tabularray}
\NewDashStyle {testdash} {on ~ 2pt ~ off ~ 2pt}
\begin{document}

\begin{table}
\begin{tblr}{
    colspec = {XXX},
    hlines = {testdash},
    vlines = {dashed},
}
  1 & 2 & 3 \\
  4 & 5 & 6 \\
  7 & 8 & 9 \\
\end{tblr}
\end{table}

\end{document}

[lvjr]

Use \NewDashStyle{testdash}{on 2pt off 2pt}.

[drcsturm]

That worked! Thank you