I try to find the mistake but i'm....

```
\documentclass[presentation]{beamer}
\usetheme{Madrid}
\usepackage[utf8]{inputenc}
\usepackage{tikz}\usetikzlibrary{calc}
\usetikzlibrary{decorations.text, decorations.pathmorphing}
\usepackage{animate}
\begin{document}
    \begin{frame}
        \newcounter{goc}
        \setcounter{goc}{0}
        \begin{animateinline}[auto,loop]{20}
            \whiledo{\thegoc<50}
            {\begin{tikzpicture}[join=round,\bfseries]
                    \pgfmathsetmacro{\g}{2.5-abs(2.5-0.1*\thegoc)}
                    \clip(-8,-2.5)rectangle (8,2.5);
                    \path(0,1)node[red,scale=2,yscale=\g]{SỬ DỤNG ANIMATE};
                    \path(0,0)node[green,scale=2,yscale=\g]{TẠO HÌNH ĐỘNG};
                \end{tikzpicture}
                \stepcounter{goc}
                \ifthenelse{\thegoc<50}{\newframe}{\end{animateinline}}
        }
    \end{frame}
\end{document}

```

[![enter image description here](https://i.stack.imgur.com/MPSQ7.png)](https://i.stack.imgur.com/MPSQ7.png)