# How could I convert items from a .bib file into bibitems in a .tex file on overleaf?

I'm writing a paper to a journal, and it asked to write all my citations in the bibitem format. On Overleaf, I have a main.tex file, and a refs.bib file. For an example citation in the refs.bib file,

@article{bartsch2008time,
title={Time-dependent transition state theory},
author={Bartsch, Thomas and Moix, Jeremy M and Hernandez, Rigoberto and Kawai, Shinnosuke and Uzer, Turgay},
volume={140},
pages={191},
year={2008}
}


I wish to convert it into a bibitem in the main.tex file, to read:

\bibitem[{Bartsch \emph{et~al.}(2008)Bartsch, Moix, Hernandez, Kawai \&
Uzer}]{bartsch2008time}
Bartsch, T., Moix, J.~M., Hernandez, R., Kawai, S. \& Uzer, T. [2008]
\enquote{Time-dependent transition state theory,} \emph{Advances in Chemical
Physics} \textbf{140},  191.


My understanding is that one can convert items from a .bib file to a bibitem in the .tex file by running: LaTeX -> BibTeX -> LaTeX -> LaTeX.

I'm not certain, however, how to accomplish this on Overleaf. Is there any means of accomplishing this (or any other methods of converting items from a .bib file into bibitems) on Overleaf?

You do not generally need to convert Bib(La)TeX references in a bib file into bibitems, and it is usually not advisable (even when some journals specify otherwise).
If you are absolutely certain that you must do so, you can use the biblatex2bibitem package. You can find detailed instructions on their webpage. In short, this is a partly manual process, as outlined, and is equivalent locally or on Overleaf.
The foregoing all assumes that you are using the more modern BibLaTeX, not BibTeX. Provided that you can find a style compatible with your journal, you ought use it. If you must use BibTeX, you may need to do this manually, as outlined (and perhaps as you were thinking). On Overleaf, this is already done for you: it produces a bbl file, and you can obtain it as outlined.