Go to OctoBot's official releases page and download the latest version for your system: Windows, Linux or MacOS. You can even use OctoBot on Arm64 Raspberry pie.
Start the downloaded executable. OctoBot opens a terminal and installs its configuration environment and the OctoBot management interface opens automatically.
On Windows, you can just double click the executable.
On Linux, first type
chmod +x OctoBot_linux_x64and then
./OctoBot_linux_x64in a terminal open next to your downloaded executable to start OctoBot.