Comment by johnisgood

Look, create an account and when you join a server that asks for your age, make sure you set the birth year to one that makes you less than 13 years old.

For what it is worth, it has to do with Discord ToS (per / by country).

In some countries you must be over 13 to use Discord, other countries 14, but if you are below, you MUST verify yourself to be able to access your Discord account after you set it to below 13. This verification process is done through sending Discord an e-mail requesting them to restore your account, with a video of yourself holding your ID card as an attachment.

The list per country can be found on Discord's website.

What I am talking about is separate from the server settings (require phone verification and/or age verification).