Drawing third, fourth and fifth degree parabolas the using “Stanli” package

Question

In the shown MWE, a parabola is drawn using the "Stanli" package. How can I shift the peak of the curve to point "D" while maintaing the tangency of the parabola with the dashed inclied line on the LHS while still being above the dashed line on the RHS.

I have noticed that the parameter of "bending position" shifts the peak of the curve vertically (as well as the parabola height parameter, where changing those 2 parabolas controls the level of tangency with the dashed lines) but how can the peak be shifted horizontally?

\documentclass{article}
\usepackage{amsmath} 
\usepackage{stanli}

\begin{document}


\begin{figure}[!htbp]
\begin{center}
\begin{tikzpicture}


%%%%%%%%%%%%%%GRID%%%%%%%%%%%%%%%%%%%%%%%%

\draw[help lines,step=0.5](0,2) grid(12,25);


%%%%%%%%%%%%%%%%%%%%Axes and scale Notations%%%%%%%%%%%%%%
\dscaling {3}{.5};
\daxis{1}{0,22.5+1.25,0}[right][above][right];

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%% Bending moment diagram%%%%%%%%%%%%%%%
%Points
\point{a-BMD}{0}{12.5};
\point{b-BMD}{12}{12.5};
\point{zero_shear_BMD}{12/3^0.5}{12.5-0.1*24};
\point{Moment_vertex}{2*12/3}{12.5-0.1*32};
\point{Moment_vertex_2}{12/2}{12.5-0.1*24};
\point{max_moment}{12/3^0.5}{12.5-0.1*24};
\point{max_moment_L}{0}{12.5-0.1*24};
\point{max_moment_R}{12}{12.5-0.1*24};

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Elements
\beam{4}{a-BMD}{b-BMD};
\beam{3}{max_moment_L}{max_moment_R};
\beam{3}{a-BMD}{Moment_vertex};
\beam{3}{Moment_vertex}{b-BMD};


\internalforces{a-BMD}{b-BMD}{0.1*0}{0.1*0}[0.1*-24*0.5][red][1]


\notation{1}{zero_shear_BMD}{D}[above];
\node[circle,inner sep=2pt,fill=black] at (zero_shear_BMD) (zero_shear_BMD) {};
\notation{1}{Moment_vertex_2}{C}[above];
\node[circle,inner sep=2pt,fill=black] at (Moment_vertex_2) (Moment_vertex_2) {};
\end{tikzpicture}
\end{center}
\end{figure} 
 

\end{document}