how to referate label in overleaf code example

Example 1: latex labels

ch:		chapter
sec:	section
subsec:	subsection
fig:	figure
tab:	table
eq:		equation
lst:	code listing
itm:	enumerated list item
alg:	algorithm
app:	appendix subsection

Example 2: figure reference latex

\ref{marker}
This prints the number assigned to the object labeled by marker