discord.js Can’t add a role to member

I wan’t my bot to give a certain role to people when they join the server. But I get some weird error I don’t really understand.
This is the code

const { GuildMember, MessageEmbed } = require("discord.js");

module.exports = {
    name: "guildMemberAdd",
    /**
     * @param {GuildMember} member
     */
    async execute(member){
        let role = member.guild.roles.cache.some(role => role.name === 'Member')
        member.roles.add(role)

        member.guild.channels.cache.get(process.env.WELCOME_MESSAGE_CHANNEL_ID).send({ 
            embeds: [
                new MessageEmbed()
                .setTitle("Welcome! :smiley:")
                .setDescription(`${member.toString()} has joined the server!n
                                Thanks for joining. Head over to <#${process.env.RULE_CHANNEL_ID}> and verify yourself in <#${process.env.VERIFY_CHANNEL_ID}> to get access to all other channels.`)
                .setThumbnail(member.user.displayAvatarURL())
                .setColor("GREEN")
            ]
        }) 
    }
}

And after someone joins I get this error message
TypeError [INVALID_TYPE]: Supplied roles is not a Role, Snowflake or Array or Collection of Roles or Snowflakes.