How to change bibliography name in report

I would suggest, if you aren't, to use the BibLaTeX package, and then you can use bibname or refname to rename your bibliography as such:

renewcommand{refname}{Webography}

Here is a MWE, as simple as possible:

documentclass[a4paper,12pt]{report}

usepackage{afterpage}
usepackage[utf8]{inputenc}
usepackage[T1]{fontenc}    

renewcommand{bibname}{Webography}

begin{document}
begin{thebibliography}{99}
    bibitem{maReference17}www.africmemoire.com/part.6-chapitre-iii-implementation-de-lapplication-949.html
    bibitem{maReference18}www.medium.com/@sidibemouhamed/10-raisons-pour-lesquelles-jaime-expo-f19b6ecfe369
    bibitem{maReference19}www.fr.wikipedia.org/wiki/PowerAMC:~:text=PowerDesigner
    end{thebibliography}
end{document}