\documentclass{article}

\usepackage[cp1250]{inputenc}
\usepackage{polski}

\begin{document}
  
\begin{center}
  {\bfseries Ligatury}:
  
  \bigskip
  
  \Huge
  
  finał
  
  \bigskip
  
  flaga
\end{center}
  
\end{document}
