\documentclass[border=2pt]{standalone}
\usepackage{amsmath,amssymb}
\usepackage{tikz}
\usepackage{tkz-euclide}
\usetikzlibrary{math,calc,intersections,through,angles,arrows.meta,shapes.geometric,shadows,quotes,spy,datavisualization,datavisualization.formats.functions,plotmarks}
\tikzset{every picture/.style={samples=300,smooth,line join=round,font=\small,thick,>={Stealth[]}}}
\begin{document}
   \begin{tikzpicture}[scale=2,
    x={(-.4cm,-.4cm)},
    y={(1cm,0cm)},
    z={(0cm,1cm)}
    ]
     \tikzmath{\r=.1;}
    \coordinate[label=45:$D$](D)at(0,0,0);
     \coordinate[label=below:$A$](A)at(1,0,0);
     \coordinate[label=right:$C$](C)at(0,1,0);
     \coordinate[label=below:$B$](B)at(1,1,0);
     \coordinate[label=left:$A_1$](A1)at(1,0,1);
     \coordinate[label=right:$C_1$](C1)at(0,1,1);
     \coordinate[label=above:$B_1$](B1)at(1,1,1);
     \coordinate[label=above:$D_1$](D1)at(0,0,1);
     \coordinate[label=left:$E$](E)at($(D)!.5!(A)$);
     \coordinate[label=right:$F$](F)at($(B)!.5!(C)$);
     \coordinate[label=above:$O$](O)at(.5,0.5,0.5);
     %\tkzDrawPoints(O);
     \filldraw[cyan](O)circle(\r);
     %\coordinate[label=left:$M$](M)at($(A1)!.5!(D)$);
     %\coordinate[label=right:$N$](N)at($(B)!.5!(C1)$);
     \draw(A1)--(B1)--(C1)--(D1)--cycle (A1)--(B1)--(B)--(A)--cycle (B1)--(C1)--(C)--(B)--cycle;
     \draw[dashed](D1)--(D)--(A) (C)--(D);
     \draw[cyan,dashed] (A1)--(E)--(F)--cycle ;
     \draw[cyan](B1)--(F);
     \draw[red,dashed](A1)--(C);
    \end{tikzpicture}

\end{document}