I used the hello,world example of tikz-feynman, which should draw a horizontal Feynman diagram
\documentclass{standalone}
\usepackage{tikz}
\usepackage{tikz-feynman}
\begin{document}
\feynmandiagram [horizontal=a to b] {
i1 -- [fermion] a -- [fermion] i2,
a -- [photon] b,
f1 -- [fermion] b -- [fermion] f2,
};
\end{document}
But got a strange output like
Can you help me?
