file­con­tents and file­con­tents* en­vi­ron­ments en­able a LATEX source file to gen­er­ate ex­ter­nal files as it runs through LATEX. <https://ctan.org/pkg/filecontents?lang=en>

filecontents-sample.tex

% Provide some test content
\begin{filecontents*}{\jobname.bib}
@article{Bao2015,
  author  = {Bao, Z. and Pan, G. and Zhou, W.},
  doi     = {10.1109/TIT.2015.2421894},
  issue   = {6},
  journal = IEEE_J_IT,
  pages   = {3413-3426},
  title   = {Asymptotic Mutual Information Statistics of
    {mimo} Channels and {CLT} of Sample Covariance Matrices},
  volume  = {61},
  year    = {2015},
}
\end{filecontents*}
\documentclass{article}
\usepackage[style = ieee]{biblatex}
\addbibresource{IEEEabrv.bib}
\addbibresource{\jobname.bib}
\begin{document}
\nocite{*}
\printbibliography

\end{document}