How do I define alt text on images in tagpdf?

Question

I installed the latest version (install-tl-20231205) and am tying to build an accessible document. The first line of the document is:

\DocumentMetadata{testphase={phase-III,math}} 

I am following the instructions here:

https://www.latex-project.org/news/2023/03/13/latex-dev-1/

I get the following warning:

Package tagpdf Warning: Alternative text for graphic is missing.
(tagpdf) Using 'eucr-fig2-eps-converted-to.eps' instead

I cannot figure out how to set the alt text for images. I found instructions for the accessibility package, but that is now defunct. I fear that it will interfere with the new methods.

Answer 1

\includegraphics has an alt key (it is more or less documentated in latex-lab-graphic.pdf):

\DocumentMetadata{testphase=phase-III}
\documentclass[a4paper]{article}
\usepackage{graphicx}
\begin{document}
\includegraphics[alt={some example image}]{example-image}
\end{document}