Can not print the sign @ when using biblatex (author year style)

I am using biblatex author year style and in my text I have an @ which biber does not like giving me error as below:

ERROR - BibTeX subsystem: C:UsersTEMPLE~1.000AppDataLocal
Tempbiber_tmp_kM22658097ff4c951e70db95e86474283432_17340.utf8, line 25, 
syntax error: found "using", expected one of: start of entry ("{" or "(") or 
quoted string ({...} or "...")

Below is the code.
To run: step1: pdflatex step 2: biber step3: pdflatex.

If you delete the symbole @ in the text the code works fine and we see the bibliography at the end.

documentclass{book}
 % to run: step1: pdflatex step 2: biber step3: pdflatex
usepackage[style=authoryear]{biblatex}
usepackage{filecontents}
begin{filecontents}{jobname.bib}
@book{mybook,
author       = { my author},
date         = { 2020},
title        = {my title},
publisher    = {city:press},
}
end{filecontents}
addbibresource{jobname}
begin{document}
I can not print  @ when using biblatex.(textcite{mybook})
printbibliography
end{document}