Based on Ivan Erik Kragh's Microsoft Word template with some alterations: https://stackoverflow.com/q/39749850/19020549
% Use XeLaTeX or LuaLaTeX as compiler.
\documentclass[11pt]{article}
\usepackage{geometry}
\usepackage{microtype}
\usepackage[skins,breakable]{tcolorbox}
\usepackage{paracol}
\usepackage{setspace}
\usepackage{fontspec}
\usepackage{fancyhdr}
\usepackage{babel}
\usepackage{lipsum}
\setmainfont{Arial}
\setstretch{1.125}
% https://stackoverflow.com/a/56310589/19020549
\newcommand\signature[2]{% Name; Department
\noindent\begin{minipage}{10cm}
\noindent\vspace{1cm}\par
\noindent\rule{5cm}{1pt}\par
\noindent\textbf{#1}\par
\noindent\vspace{1pt}\par
\noindent#2%
\end{minipage}}
\newgeometry{top=0.7in, bottom=0.7in, left=0.8in, right=0.8in}
\pagestyle{fancy}
\begin{document}
\setlength{\columnsep}{0.3in}
\setcolumnwidth{3.1in, 1.07in}
\begin{paracol}{2}
\begin{tcolorbox}[blanker, breakable, width=\linewidth]
1600 Pennsylvania Avenue, \\
Washington, D.C., \\
USA
\noindent\vspace{4cm}\par
\textbf{Dear Sir/Madam,} \\
\lipsum[1][1-4] \\
\lipsum[2][1-5]
\noindent\vspace{1cm}\par
Sincerely, \\
\signature{Quandale Dingle}{Tlf.: 089 011 0425 \\ E-mail: quandale.dingle@hotmail.com}
\end{tcolorbox}
\switchcolumn
\begin{tcolorbox}[blanker, breakable, width=\linewidth]
{
7th of September, 2022 \\
Quandale Dingle \\
221B Baker St., \\
London
}
\end{tcolorbox}
\end{paracol}
\fancyhf{}
\renewcommand{\headrulewidth}{0pt}
\fancyhf[OFC]{\normalsize Quandale Dingle - 089 011 0425}
\end{document}