documentclass{book}
usepackage{graphicx}
usepackage{wrapfig}
begin{document}
mainmatter
chapter{Authors}
begin{wrapfigure}{r}{0.3textwidth}
includegraphics[width=0.28textwidth]{graphics/jimphoto}
end{wrapfigure}
end{document}

! LaTeX Error: File `graphics/jimphoto' not found.
See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...

l.8 ...cs[width=0.28textwidth]{graphics/jimphoto}

Preamble{xhtml}
DeclareGraphicsExtensions{.jpg,.png,.gif,.svg}
begin{document}
EndPreamble

make4ht -c myconfig.cfg filename.tex