CircuiTikZ: How to draw contactor coil?

It is possible using TiKz library tikz-relay (https://ctan.org/pkg/tikz-relay):

\documentclass[margin=3mm]{standalone}
\usepackage{circuitikz,tikz}
\usetikzlibrary{circuits.ee.IEC.relay}
\begin{document}
\begin{circuitikz}[circuit ee IEC relay,thick]
\draw (0,0) to [relay coil={info=$K_1$,term=A1,term'=A2}] (0,1);
\end{circuitikz}
\end{document}

In circuitikz, you can use generic which is a rectangular blob:

\documentclass[border=10pt]{standalone}
\usepackage[siunitx, RPvoltages]{circuitikz}
%\usepackage[siunitx, RPvoltages]{circuitikzgit}
\begin{document}
\begin{circuitikz}[
    ]
    \ctikzset{relaycoil/.style={bipoles/generic/width=0.3, 
        bipoles/generic/height=0.4}}
    \draw (0,0) to[generic=K1, relaycoil, name=k1] ++(0,2);
    \node [rotate=90, above right, font=\scriptsize] at(k1.right) {A1};
    \node [rotate=90, above left, font=\scriptsize] at(k1.left) {A2};
\end{circuitikz}
\end{document}

Notice that the definition of width and height are thought for the element in a horizontal position.