gives role discord.js v12 code example

Example: how to give roles discord.js

let role = message.guild.roles.find(r => r.name === "Role Name");

// Let's pretend you mentioned the user you want to add a role to (!addrole @user Role Name):
let member = message.mentions.members.first();

// or the person who made started the command: let member = message.member;

//adds the role
member.roles.add(role)