Hello.

Currently, Inkscape only exports in PNG, SVG, TIFF, PDF, JPG and WEBP formats.

I really wish Inkscape could import .webp. After all, PNG and TIFF are Jurassic period files, and are no longer practical given the file size they occupy. WEBP replaces these perfectly.

If you are referring to using webp in SVG files (embedded) that is not supported by the svg standard. However I found out recently that browsers do support this due to their relaxed standards. 

SVG only supports png/jpeg ( and gif behaviour is undefined )

If you are just referring to importing a variety of bitmap formats - into Inkscape (which will arrive on canvas as png).

Then I wrote this ages ago: 

It imports most exotic formats, also animated gif.

https://gitlab.com/inklinea/impex

To work around this limitation, you can convert your WEBP files to one of the supported formats, such as PNG or SVG, using external conversion tools or online converters. Once you have converted the file, you can import it into Inkscape for further editing.

Keep in mind that software capabilities and features may change over time, so it's worth checking the latest version of Inkscape or any relevant updates to see if support for WEBP import has been added.