First of all, the template loads the IEEE class IEEEtran but then uses the outdated (and I think unofficial) ieeetr bibliography style. IEEEtran comes with its own set of official bibliography styles, so you should look into using \bibliographystyle{IEEEtran}. (In fact that does not matter too much for the question at hand...)
In general I recommend not using publisher/journal classes like IEEEtran unless you plan to submit to that publisher/journal. In which case you should use the class exactly as documented.
Grey literature like this would normally not use the @article entry type. Only papers published in an academic journal should be @articles (@article is also OK for articles in non-academic journals, magazines and newspapers).
For reports like this, the best choice is usually @techreport. btxdoc says the following about @techreport
techreport A report published by a school or other institution, usually numbered within a series.
Required fields: author, title, institution, year.
Optional fields: type, number, address, month, note
In case of https://www.imf.org/en/Publications/WEO/Issues/2016/12/31/World-Economic-Outlook-April-2009-Crisis-and-Recovery-22575 I'd probably go with
\documentclass{IEEEtran}
\begin{filecontents}{\jobname.bib}
@techreport{imf09,
author = {{International Monetary Fund}},
title = {World Economic Outlook, {April} 2009: Crisis and Recovery},
year = {2009},
type = {World Economic and Financial Surveys},
}
\end{filecontents}
\begin{document}
\cite{imf09}
\bibliographystyle{IEEEtran}
\bibliography{\jobname}
\end{document}

You'll notice that I didn't include the (according to btxdoc) required field institution, because that would result in a doubled 'International Monetary Fund', which I found awkward
@techreport{imf09,
author = {{International Monetary Fund}},
title = {World Economic Outlook, {April} 2009: Crisis and Recovery},
year = {2009},
type = {World Economic and Financial Surveys},
institution = {International Monetary Fund},
address = {Washington, D.C.},
}
.bibentry should not automatically cause (La)TeX to want to importbiblatex. The.bibentry is syntactically well formed and can be used with BibTeX andbiblatex. (Semantically it can be improved, but that is the point of my answer.) – moewe May 19 '20 at 06:53