Converting to OverpassQL a request with the convert statement produces too many "

[naomap]

Here is a request that uses the convert statement to produces admin centre point together with tags coming from the admin boundaries : https://overpass-turbo.eu/s/1Vds

The request works fine, however exporting it to compact OverpassQL produces the following string:
[out:csv("nom","pop","pop_date","lat","lon")];area["admin_level"="6"]["ref:INSEE"="44"];relation["boundary"="administrative"]["admin_level"="8"](area);foreach->.c{node(r.c:"admin_centre");convert Commune nom=c.u(t[""name""]),pop=c.u(number(t[""population""])),pop_date=c.u(t[""population:date""]),lat=lat(),lon=lon();out;}

along with this url :
https://overpass-api.de/api/interpreter?data=%5Bout%3Acsv%28%22nom%22%2C%22pop%22%2C%22pop%5Fdate%22%2C%22lat%22%2C%22lon%22%29%5D%3Barea%5B%22admin%5Flevel%22%3D%226%22%5D%5B%22ref%3AINSEE%22%3D%2244%22%5D%3Brelation%5B%22boundary%22%3D%22administrative%22%5D%5B%22admin%5Flevel%22%3D%228%22%5D%28area%29%3Bforeach%2D%3E%2Ec%7Bnode%28r%2Ec%3A%22admin%5Fcentre%22%29%3Bconvert%20Commune%20nom%3Dc%2Eu%28t%5B%22%22name%22%22%5D%29%2Cpop%3Dc%2Eu%28number%28t%5B%22%22population%22%22%5D%29%29%2Cpop%5Fdate%3Dc%2Eu%28t%5B%22%22population%3Adate%22%22%5D%29%2Clat%3Dlat%28%29%2Clon%3Dlon%28%29%3Bout%3B%7D%0A

The keys in the t[] operators, e.g. t["name"], get their quotes doubled, e.g. nom=c.u(t[""name""]). This produces several « Error: line 1: parse error: Operator expected, but "name" found. » when running the request.