Double check that discord is logged into your account, and make sure to select the correct account and server you want to link to when linking the discord bot.
Unable to invite your own bot using "Generated URL" in the 3-2 part
You did not add your bot before the step
Double check whether you added your own bot in the previous steps.
[macOS] Install and Updating Errors
Discord only supports MacOS 10.11 and up (El Capitan) or above