When try to install anything (not only brave browser) through the command line it says "Malformed entry 1 in list file /etc/apt/sources.list.d/brave-browser-release-.list"

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From what I think is that related thread, since you’re having the same error, the same suggestion applies - check what’s shown in the flagged file. If you’re using Ubuntu or another Debian-based linux:

let’s take a peek at your sources list that is flagged as having a malformed entry by doing
sudo less /etc/apt/sources.list.d/brave-browser-release.list

Make sure there’s no stray characters if you copy and paste. Less should give you a single entry like this (type q to get out of it):

deb [arch=amd64] https://brave-browser-apt-release.s3.brave.com/ stable main

Is that what you get?