footnote in Math Environment

Question

\documentclass[12pt]{article} 
\usepackage{amstext, amsmath}
\usepackage{chemarrow}

\begin{document}
\let\rightarrow\chemarrow
Begin $\xrightarrow[\text{Text below the arrow}\footnote{this is footnote}]{\text{Text above the arrow}}$ end
\end{document}

It shows the footnote number but does not actually show the footnote at the bottom

Answer 1

use \footnotemark and \footnotetext

\documentclass[12pt]{article} 
\usepackage{amstext, amsmath}
\usepackage{chemarrow}

\begin{document}
\let\rightarrow\chemarrow
Begin $\xrightarrow
  [\text{Text below the arrow\footnotemark[1]}]
  {\text{Text above the arrow}}$ end
\footnotetext[1]{this is footnote}\stepcounter{footnote}

foo\footnote{bar}
\end{document}