Url Rewrite Provider on Azure Web App
You can't install something on a Web App unless it's packaged as an Extension (see: https://www.siteextensions.net/). I don't see those providers as being packaged so you'd have to create a package yourself or look for an alternative solution.
Having said this, you could try package the assemblies in a Web App you deploy and see if that works as expected (it's not something I've tried in this exact scenario).
It may be hacky, but you could try pulling the DLL and its depencies into your BIN folder and deploy. You don't get the nice UI to manage, but worth a shot.