How to create a .bib file with only citations of a current article (out of the main .bib file containing 100-200+ citations)?

Question

I'm writing an article and have to communicate the references in a .bib format with my co-authors. I have a single central .bib file (where there are 100-200+ citations) but want to give the .bib file containing only the (approx) 20 citations cited in the article. Is there a command/manoeuver/shorcut to generate such a file? I use vim as a text editor and use terminal for commands (such as pdflatex as well as biber for citation management. I looked at this question: and ran sequentially:

pdflatex filename
bibexport filename

I got the following message:

This is BibTeX, Version 0.99d (TeX Live 2019)
The top-level auxiliary file: bibexp.1620677239.aux
I found no \citation commands---while reading file bibexp.1620677239.aux
I found no \bibdata command---while reading file bibexp.1620677239.aux
I found no \bibstyle command---while reading file bibexp.1620677239.aux
(There were 3 error messages)

as well as a empty file bibexport.bib

I then tried the following command:

$ biber --output_format=bibtex --output_resolve report.bcf

but got the following output:

INFO - This is Biber 2.12
INFO - Logfile is 'report.blg'
INFO - Reading 'report.bcf'
INFO - Found 28 citekeys in bib section 0
INFO - Looking for bibtex format file '/Users/path/to/biblio.bib'
INFO - LaTeX decoding ...
INFO - Found BibTeX data source '/Users/path/to/biblio.bib'
WARN - month field 'aug' in entry 'Baumgartner_2017' is not an integer - this will probably not sort properly.
WARN - month field 'jun' in entry 'Nishimura_2014' is not an integer - this will probably not sort properly.
WARN - month field 'jan' in entry 'Baumgartner_2009' is not an integer - this will probably not sort properly.
WARN - month field 'dec' in entry 'Baumgartner_2016' is not an integer - this will probably not sort properly.
WARN - month field 'oct' in entry 'O_Sullivan_2013' is not an integer - this will probably not sort properly.
WARN - month field 'aug' in entry 'Nishimura_2002' is not an integer - this will probably not sort properly.
WARN - month field 'jun' in entry 'Fougeres_2012' is not an integer - this will probably not sort properly.
WARN - month field 'apr' in entry 'Boulain_2002' is not an integer - this will probably not sort properly.
WARN - month field 'dec' in entry 'Clavel_2013' is not an integer - this will probably not sort properly.
WARN - month field 'apr' in entry 'Clavel_2010' is not an integer - this will probably not sort properly.
WARN - month field 'sep' in entry 'Rao_2018' is not an integer - this will probably not sort properly.
WARN - month field 'jan' in entry 'Ha_2018' is not an integer - this will probably not sort properly.
ERROR - BibTeX subsystem: /var/folders/jq/yyp9q2fs1z5780k9l1_2ph4r0000gn/T/BNmPZUubEF/biblio.bib_16500.utf8, line 29, syntax error: found ":", expected end of entry ("}" or ")") (skipping to next "@")
INFO - WARNINGS: 12
INFO - ERRORS: 1

Here ar the first 47 lines of the biblio.bib file:

@article{Howell_2015,
    doi = {10.1530/erp-15-0005},
    url = {https://doi.org/10.1530%2Ferp-15-0005},
    year = 2015,
    month = {mar},
    publisher = {Bioscientifica},
    volume = {2},
    number = {1},
    pages = {R37--R44},
    author = {Neil Howell and William Bradlow},
    title = {Surgical management of left ventricular outflow obstruction in hypertrophic cardiomyopathy},
    journal = {Echo Research and Practice}
}
@article{Chahal_2015,
    doi = {10.1016/j.jcmg.2015.04.021},
    url = {https://doi.org/10.1016%2Fj.jcmg.2015.04.021},
    year = 2015,
    month = {oct},
    publisher = {Elsevier {BV}},
    volume = {8},
    number = {10},
    pages = {1133--1139},
    author = {Navtej S. Chahal and Maria Drakopoulou and Ana M. Gonzalez-Gonzalez and Ramasamy Manivarmane and Rajdeep Khattar and Roxy Senior},
    title = {Resting Aortic Valve Area at Normal Transaortic Flow Rate Reflects True Valve Area in Suspected Low-Gradient Severe Aortic Stenosis},
    journal = {JACC: Cardiovascular Imaging}: Cardiovascular Imaging}
}
@article{Caballero_2017,
    doi = {10.1016/j.echo.2016.10.006},
    url = {https://doi.org/10.1016%2Fj.echo.2016.10.006},
    year = 2017,
    month = {jan},
    publisher = {Elsevier {BV}},
    volume = {30},
    number = {1},
    pages = {28--35},
    author = {Luis Caballero and Daniel Saura and Mar{'{\i}}a Jos{'{e}} Oliva-Sandoval and Josefa Gonz{'{a}}lez-Carrillo and Mar{'{\i}}a Dolores Espinosa and Miguel Garc{'{\i}}a-Navarro and Mariano Vald{'{e}}s and Patrizio Lancellotti and Gonzalo de la Morena},
    title = {Three-Dimensional Morphology of the Left Ventricular Outflow Tract: Impact on Grading Aortic Stenosis Severity},
    journal = {Journal of the American Society of Echocardiography}
}

what am I doing wrong?