To make RDP file open on your browser, instead of downloading, you have to download the file type once, then right after that download, look at the status bar at the bottom of the browser. Go to Preferences → Applications (or paste about:preferences#applications in your address bar) and change Action to Always ask for telnet, capture and docker Content Types. NOTE: Path to the Preferences file will be different for Chromium and other Chromium-based browsers.
