Cannot render basic diagram

[peterelbert]

I’m having difficulty rendering latex tikz-cd diagrams. Could anyone help?

I feel like this should work:

\usepackage{tikz-cd}

\begin{document}

\begin{tikzcd}

A \arrow[rd, "f"] & B

\end{tikzcd}

\end{document}

But it’s not rendering.

I copied and pasted the code example from here:
https://forum.obsidian.md/t/tikzcd/65733

And that code renders perfectly. I am wondering if the problem is the body of the diagram rather than any of the latex headers?

[JacobH140]

Any luck on this? Drawing arrows in the fashion \draw[->] (A) -- (B) node[midway, above] {$f$}; works for me, but actually using \arrow does not.