\documentclass{article}
\pagestyle{empty}
\usepackage{geometry,fontspec,tikz}
\geometry{a6paper,landscape,hmargin={1cm,1cm},vmargin={1cm,1cm}}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{ebgaramond}
\usepackage{etoolbox}

\newtoggle{Vietnamese}

\ifdefined\ViFlag
  \toggletrue{Vietnamese}
\else
  \togglefalse{Vietnamese}
\fi

\usetikzlibrary{fadings}
% \tikzfading[name=fade right, left color=transparent!0, right color=transparent!100]
% \tikzfading[name=fade in, inner color=transparent!200, outer color=transparent!0]
\pgfdeclarehorizontalshading{FOne}{100bp} {
  color(0bp)=(pgftransparent!0);
  color(25bp)=(pgftransparent!0);
  color(50bp)=(pgftransparent!80);
  color(100bp)=(pgftransparent!100)}

\pgfdeclarefading{myfading}{\pgfuseshading{FOne}}

\setlength\parindent{0pt}

\begin{document}
\begin{tikzpicture}[overlay,remember picture]
  \node[anchor=east,inner sep=0pt] (pic) at (current page.east)
  {\includegraphics[height=\pdfpageheight]{027-028}};
  \fill[white,path fading=myfading] (pic.north west) rectangle (pic.south east);
  \iftoggle{Vietnamese}{
    \node[anchor=south east, inner sep=0pt] (qrEvent_vi) at (pic.south east)
    {\includegraphics[height=2.5cm]{qrEvent_vi}};
  }{
    \node[anchor=south east, inner sep=0pt] (qrEvent_en) at (pic.south east)
    {\includegraphics[height=2.5cm]{qrEvent_en}};
  }
\end{tikzpicture}%

\obeylines%
{\addfontfeatures{Scale=2.8,LetterSpace=9,Color=red}
  \iftoggle{Vietnamese}{ THIỆP MỜI }{ INVITATION }}

\bigbreak
\textit{%
  \iftoggle{Vietnamese}{
    Trân trọng kính mời bạn

    dự tiệc cưới của chúng tôi,

    Nam và Hương.
  }{
    Dear friend,

    We'd love to invite you to our wedding reception.

    Sincerly,

    Nam and Huong.
  }
}

\vfill
  \iftoggle{Vietnamese}{
    {\addfontfeatures{Scale=1.4,LetterSpace=5,Color=red}\scshape Bao giờ?}
    \textit{%
      Chủ Nhật, ngày 1, tháng 3, năm 2020
      4\kern.5pt:\kern.5pt00 chiều
    }
    \medbreak
    {\addfontfeatures{Scale=1.4,LetterSpace=5,Color=red}\scshape Ở đâu?}
    \textit{%
      Trung tâm nhà hàng tiệc cưới Âu Cơ,

      1A Nguyễn Hữu Cầu, Phường Ngọc Châu,

      Thành phố Hải Dương, Hải Dương
    }
  }{
    {\addfontfeatures{Scale=1.4,LetterSpace=5,Color=red}\scshape when?}
    \textit{%
      March 1\/\rlap{,}\textsuperscript{st} 2020
      4\kern.5pt:\kern.5pt00 pm
    }
    \medbreak
    {\addfontfeatures{Scale=1.4,LetterSpace=5,Color=red}\scshape where?}
    \textit{%
      Auco Convention Center,

      1A Nguyen Huu Cau Str, Ngoc Chau Ward

      Hai Duong City, Hai Duong
    }
  }

\end{document}