Indentation in tcolorbox package

Ignasi's comment works if you use

before upper={\parindent15pt}

And find the value by

\showthe\parindent

in the log.

Code:

\documentclass[a4paper]{book}

\usepackage{lipsum}
\usepackage[most]{tcolorbox}

\begin{document}

\chapter{Example with \texttt{tcolorbox}}
\lipsum[1-8]
%\showthe\parindent  %%,---- find \parindent
\begin{tcolorbox}[breakable,enhanced,before upper={\parindent15pt}]
\lipsum[9-14]
\end{tcolorbox}

\end{document}

Following up on user11232's answer, you can add

before upper={\parindent15pt\noindent}

to disable indentation of the first paragraph in the box.