tikz3d-tetrahedron

\documentclass[]{standalone}

\usepackage[]{graphicx}

\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.17}
\tikzset{>=latex}
\usetikzlibrary{arrows,arrows.meta}
\usepackage{steinmetz}
\newcommand*{\equal}{=}

\usepackage{tikz-3dplot}
\usetikzlibrary{decorations.markings}

\tikzset{->-/.style={decoration={
  markings,
  mark=at position #1 with {\arrow{>}}},postaction={decorate}}}

\begin{document}
\tdplotsetmaincoords{25}{45}
\begin{tikzpicture}[tdplot_main_coords,scale=2]
  \draw[thick,-]  (0,0,0) node [below] {A} -- (2,0,2) node [below] {B} -- (2,2,0) node[right] {C}  -- (0,0,0);  
  \draw[thick,-] (0,0,0)  -- (2,2,0) -- (0, 1, 1) node [above] {D} -- (2,0,2);
  \draw[thick,-] (0,0,0) -- (0,1,1);
\end{tikzpicture}
\end{document}