# Sans serif bold-faced small caps in section title

I use PT Sans as my sans serif font. Thus, it is used in part, chapter, and section titles and so on. In my titles, I use small caps. As far as I understand it, the titles are boldfaced and it seems like PT Sans does not support boldfaced small caps. I read that KP-Fonts supports bf small caps but I can't get it to work in my MWE. The following MWE is still with PT Sans:

\documentclass[11pt]{book}

\usepackage{fontspec}
\setsansfont{PT Sans}

\begin{document}

\section{Title: \textsc{this should be in small caps}}

\begin{enumerate}
\item Test: \textsc{this is indeed in small caps because it's in serife}
\item Test\textsubscript{\textsc{this is indeed in small caps because it's in serife}}
\item \textsf{Test: \textsc{this should be in small caps}}
\item \textbf{\textsf{Test: \textsc{this should be in small caps}}}
\item \textsf{\textbf{Test: \textsc{this should be in small caps}}}
\item Test\textsubscript{\textbf{\textsf{\textsc{this should be in small caps}}}}
\item Test\textsubscript{\textsf{\textbf{\textsc{this should be in small caps}}}}
\end{enumerate}

\end{document}

This gives me the following output:

So my main question is: How do I get bold-faced small caps in a sans serif font for part, chapter, and section titles etc.?

I'm a Latex novice and also new to this site. I hope, I did everything correctly with the MWE and the output.

Also, of course, I searched for solutions for weeks and I found similar questions here but I'm still not good enough to get it working in Latex.

There are three engines to produce a PDF from your LaTeX file: pdfTeX, XeTeX and LuaTeX.

It seems you haven't used pdfTeX in your example. pdfTeX still has the advantage of speed and there is a large catalog of fonts you can easily use with pdfTeX, see here: The LaTeX Font Catalogue.

If your font doesn't provide small caps, let's pick one which does.

I picked the noto font, which provides serif and sans-serif glyphs and whatnot else.

MWE for pdfTeX:

\documentclass[english]{scrbook}

\usepackage{babel}
\usepackage[T1]{fontenc}
\usepackage{noto}

\usepackage[tracking=true]{microtype}
\SetTracking{encoding= * , shape = sc}{50}

\usepackage{microtype}
\usepackage{blindtext}

\begin{document}
\blinddocument{}
\end{document}

Works also with LuaTeX:

\documentclass[english]{scrbook}

\usepackage{babel}
\usepackage{fontspec}
\usepackage{noto}

\usepackage[tracking=true]{microtype}
\SetTracking{encoding= * , shape = sc}{50}

\usepackage{microtype}
\usepackage{blindtext}