jou class apa6, problem with one column

Question

I have a problem trying to insert an equation cause is too large, so, I use the enviroment multicols, and @twocolumnfalse, but when I run the document, the precendent text its displayed in one column and the other is empty.

I try with the environment widetext but its produce the error "enviroment undefined", I'm learning this so I guess that I have a problem with the package, also I try to get the package \usepackage{widetext}, but its produce the error

"File widetext.sty not found",

again I guess that I dont have the package in my computer but I don't know how to get it. This is the code that I'm using:

\documentclass[jou]{apa6}

\usepackage[spanish]{babel}
\usepackage[latin1]{inputenc}
\usepackage{hyperref}
\usepackage{braket}
\usepackage{graphicx}
\usepackage{mathrsfs}
\usepackage{widetext}
\usepackage{enumitem}

\urlstyle{same}

\begin{document}

a lot of text

\begin{widetext}
\begin{equation}
EQUATION...
\end{equation}
\begin{widetext}

\end{document}