manage_roles in discord.js code example
Example 1: get discord.js role
let role = message.guild.roles.cache.find(r => r.id === "Role ID");
// The member you want to add the role to
let member = message.mentions.members.first();
// Add role to the member
member.roles.add(role);
// Or add it to yourself
message.author.roles.add(role);
Example 2: if member has role discord.js
let allowedRole = message.guild.roles.find("name", "rolename");
if (message.member.roles.has(allowedRole.id) {
// allowed access to command
} else {
// not allowed access
})