\documentclass[11pt,spinewidth=25mm,coverwidth=150mm,coverheight=200mm,flapwidth=60mm]{bookcover}
\usepackage{contour,lipsum}
\contourlength{1pt}
\definecolor{lightbrown}{RGB}{176,88,0}
\colorlet{title}{yellow!60!black}
\begin{document}

% Black background color on the whole cover
\setbookcover{bgcolor}{whole}{color=black}

% Brown background picture on the whole cover, without the flaps
\setbookcover{bgpic}{whole without flaps}{./figures/bg.jpg}

% Vertical light brown transparent trails on the back cover by a tikz code
\setbookcover{bgtikz}{back}{
    \fill[opacity=0.3,color=lightbrown] 
    (0mm,0mm) rectangle (20mm,210mm) (100mm,0mm) rectangle (150mm,210mm);}
    
% Vertical light brown transparent trails on the front cover by a tikz code
\setbookcover{bgtikz}{front}{
    \fill[opacity=0.3,color=lightbrown] 
    (0mm,0mm) rectangle (50mm,210mm) (130mm,0mm) rectangle (150mm,210mm);}
    
% Remark 
\setbookcover{fgfirst}{above front}{\bfseries\color{blue}SAMPLE DUST JACKET}
    
% Text on the front cover
\setbookcover{fgfirst}{front}{
    \centering
    \vspace{60mm}
    \color{title}\sffamily\bfseries
    \resizebox*{50mm}{8mm}{\contour[120]{black}{Rose Taylor}}
    \par
    \vspace{20mm}
    \resizebox*{90mm}{40mm}{\parbox{35mm}{
        \centering
        \contour[120]{black}{PROBABILITY}\\
        \contour[120]{black}{THEORY}\\}}}
        
% Picture (cards.png) on the front, behind the title
\setbookcover{fgsecond}{front}{
    \vspace{70mm}
    \centering
    \includegraphics[width=8cm]{./figures/cards.png}}  

% Text on the spine
\setbookcover{fgfirst}{spine}{
    \vfill
    \centering
    \rotatebox[origin=c]{90}{\contour[120]{black}{
        \color{title}\huge\sffamily\bfseries 
        Rose Taylor -- Probability Theory}}
    \vfill}
    
% Text on the back cover
\setbookcover{fgfirst}{back}{
    \centering
    \vspace{20mm}
    \parbox{110mm}{\color{white}\lipsum[1]}}
        
% Text and picture (dice.png) on the front flap
\setbookcover{fgfirst}{front flap}{
    \centering
    \vspace{20mm}
    \parbox{40mm}{\color{white}\lipsum[2]}
    \vfill
    \includegraphics[width=30mm]{./figures/dice.png}
    \vspace{10mm}}
    
% Text on the back flap
\setbookcover{fgfirst}{back flap}{
    \centering
    \vspace{20mm}
    \parbox{40mm}{\color{white}\lipsum[2]}}

% Making the dust jucket
\makebookcover

\end{document} 