\documentclass{article}
\usepackage[french]{babel}
\usepackage[backend=biber, style =authoryear]{biblatex}
\DefineBibliographyStrings{french}{%
pages = {pp\adddot},
in ={\emph{in}},
volume={vol\adddot},
number={n°}
}
\DeclareFieldFormat{no}{\bibsstring{number}#1}
\DeclareFieldFormat{vol}{\bibsstring{volume}~#1}
\renewbibmacro*{volume+number+eid}{%
\addcomma\space%
\printfield[vol]{volume}%
\setunit{\addcomma\space}%
\printfield[no]{number}%
\setunit{\addcomma\space}%
\printfield{eid}}
\begin{filecontents*}[overwrite]{\jobname.bib}
@article{einstein,
author = {Einstein, A.},
title = {Die Grundlage der allgemeinen Relativitätstheorie},
journal = {Annalen der Physik},
volume = {354},
number = {7},
doi = {10.1002/andp.19163540702},
pages = {769--822},
year = {1916}
}
\end{filecontents*}
\addbibresource{\jobname.bib}
\addbibresource{biblatex-examples.bib}
\begin{document}
\cite{einstein}
\cite{bertram}
\printbibliography
\end{document}
![alt text][1]
[1]: https://texnique.fr/osqa/upfiles/Screen_Shot_2021-04-30_at_15.48.07.pnghttps://texnique.fr/osqa/upfiles/Screen_Shot_2021-04-30_at_15.53.23.png
