http://www.shunyweb.info/convert.php
Anyway, what your PC spec? If you still using Windows 7 or 8 or 10 in 32 bit, visit here and download 32 bit Desmume!
https://www.emucr.com/2020/03/desmume-git-20200306.html
I warning you because this is OLD GIT and doesn't support any features and some bugs which was fixed on latest version on 64 bit Desmume only.
Unless, upgrade your PC and use 64 bit Windows 7, 8 or 10 right now. Right now, use No$gba for now if your still using 32 bit oldies PC.