Include the textcomp package for backward compatibility

Co-authored-by: Tanavit <tanavit@example.com>

assets/manual/manual.tex

@@ -4,6 +4,7 @@
 \fi
 \usepackage[a4paper,margin=2cm]{geometry}
 \usepackage[T1]{fontenc}
+\usepackage{textcomp}
 \ifx\HCode\undefined
 \usepackage{beton}
 \usepackage{eulervm}