witharrows package aligning equation to the left

Question

I'm using witharrows package to document my steps in solving an equation like so:

    \begin{enumerate}[label=(\alph*)]
    \item
    \begin{flalign*}
    \begin{WithArrows}[format=l, jot=4pt]
    \sin^2x &= 3 \cdot \cos^2x \Arrow[]{$\div \cos^2x$} &\\[4pt]
    \frac{\sin^2x}{\cos^2x} &= 3
    \end{WithArrows}
    \end{flalign*}
    \end{enumerate}

I wish for the equation to be aligned to the left so I set an anchor point in the end as-well &.

The result is centered and the arrows are overlapping the equations and I'm not sure why:

I get the following errors:

Package witharrows Error: You should use the command \Arrow only in the last(witharrows) {WithArrows}. ^^I\end{flalign*}
Package witharrows Error: Your environment {WithArrows} has 1 columns and

Which I cannot understand.
Would appreciate help deciphering what it means and how to solver it.
Thanks in advance.

EDIT: full example: https://pastebin.com/hshSaUra

Answer 1

Maybe you want that:

\documentclass{article}

\usepackage{witharrows}
\usepackage{enumitem}
\usepackage{amsmath}

\begin{document}

\begin{enumerate}[label=(\alph*)]
\item
$\begin{WithArrows}[format=l, jot=4pt]
\sin^2x = 3 \cdot \cos^2x \Arrow[]{$\div \cos^2x$} \\[4pt]
\frac{\sin^2x}{\cos^2x} = 3
\end{WithArrows}$
\end{enumerate}

\end{document}