\documentclass{standalone}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{fourier}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}

\begin{document}

\begin{tikzpicture}
\begin{axis}[
  axis lines=center,
  axis equal,
  xlabel=$x$,
  ylabel=$y$,
  zlabel=$z$,
  xtick distance=1,
  ytick distance=1,
  ztick distance=1,
  zmin=0,
  colormap={mygray}{color=(black!10) color=(black!70)},
  mesh/cols=4,
  view={105}{25},
]
\addplot3[surf, opacity=0.5] table { 
  x  y  z
  0  0  1.5
  0  1  2
  0  2  2
  0  3  2.5
  1  0  2
  1  1  2
  1  2  2
  1  3  3
  2  0  2
  2  1  2
  2  2  2
  2  3  2
  3  0  1
  3  1  1
  3  2  2
  3  3  2.5
};
\end{axis}
\end{tikzpicture}

\end{document}