I am making a book with all my music scores I make with “Musescore.” All these scores are a png file covering a whole page. So ...
How do I number the pages ?
Automatically every time I add a page.
Staring from page “0” (Don’t want the index page to be numbered.)

I did searched the net up and down to find an answer before I came here. 

This is a chore that might be better to use Scribus.

In any case, if the Musescore files are still around, I'd save the pages as SVG rather than PNGs.

For numbering, maybe this: https://inkscape.org/~Moini/%E2%98%85nextgenerator-replace-export, but maybe there is a better way.

Took a look at that link but I have no idea Whiskey Tango Foxtrot it is all about.
Musescore also exports .svg ... did the test ... also works. The difference is that .svg only exports the content and .png the whole page. A whole page snaps to the boundary of the page and the .svg I have to position myself. 

Went to Scibus to make my score book … that is an awesome tip. Incscape is cool but obviously it has still a lot of work.

Thanks for the reply.

Horses for courses... Scribus is for paged documents, Inkscape is an illustration tool.

The .png may be easier to align, but the filesize and resolution may be a compromise.

This should still work.

Make you manually check the final product if you are publishing though. 

https://gitlab.com/inklinea/page-numbering