Tip :
if not properly "installed in your path” as explained
in Installing adb and fastboot on Windows PC,
or in Installing adb and fastboot on macOS and Linux PC,
extract the .ZIP, open the terminal from the newly created “platform-tools” folder
and simply add ./ at the beginning of all your adb or fastboot commands, it will use the binary included into the relative folder (the latest version you just downloaded) instead of the version installed on your system (that can be outdated)