Issue adding user to guild with GuildMemberManager#add

utils.CommunicationManager.on("addUser", async (data, reply) => {
        /*
          In this, data.userId is confirmed to be my user ID (267380687345025025)
          data.accessToken is confirmed to be a legitimate access token with the guilds.join scope.
        */
    try {
        const guild = await client.guilds.fetch(config.discord.mcp_guild);
        await guild.members.add(data.userId, {
            accessToken: data.accessToken,
            fetchWhenExisting: true,
        });
        reply({});
    } catch(err) {
        console.error(`Error while adding user to guild:`);
        console.error(err);
    }
});

Error while adding user to guild:
TypeError: Cannot read properties of undefined (reading 'id')
    at GuildMemberManager._add (/Users/tyler/GitHub/mcp/discord/node_modules/discord.js/src/managers/GuildMemberManager.js:39:52)
    at GuildMemberManager.add (/Users/tyler/GitHub/mcp/discord/node_modules/discord.js/src/managers/GuildMemberManager.js:137:14)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async /Users/tyler/GitHub/mcp/discord/app.js:18:3