I have drawn multiple polygons (with Bezier curve tool) over an image using Inkscape, and I want to extract the area of each polygon in px^2 to a text file (txt, csv). On Inkscape I can only use the Measure Path tool and add the calculated area to the canvas as a path, and then type it to text, which is very repetitive (and very susceptible to typing errors).

I have a weird problem with Inkscape.
I have an svg that, when I open it in Inkscape I see it correctly, but if I try opening it in a web browser I see objects that do not exist.
Basically, I had a svg that worked fine, I changed the text of some text objects, but when I save it and open it in the browser I see the previous text and the current one.
For example, this is what I see in Inkscape: