In the browser's log it wrote an error:
Can't open portal file chooser: GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod
I decided to leave the solution to this problem here because it is not found in the search engine
SOLVED!!!
You should have installed the xdg-desktop-portal-gtk package as well as the xdg-desktop-portal package (preferably)
In my case it is:
su
apt install xdg-desktop-portal-gtk xdg-desktop-portal
!!! Make sure to reboot your system afterwards !!!
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