Having trouble using default emoji for discord in discord.js reaction role

Question

I am making a role reaction and it is not working with default emojis no matter what I try. This is what I have right now if someone could help me out. It does work with custom emojis though. Here is my reaction role file that I have with the default emoji. It doesn't give any errors but it just says undefined where the emoji is supposed to go.

const firstMessage = require('./first-message')

module.exports = client => {

const channelD = '895718398791667722'

const getEmoki = emojiName => client.emojis.cache.find(emoji => emoji.name === emojiName)

const digitalEmoji = '🔒'


const emojis = {
    lock : '🔒Digital\'s Daring Detective Decoder'
}

const reactionIds = []

let emojiText = '**Congrats!**\n***Add a reaction to claim a role***\n'
for (const key in emojis){

    const emoji = getEmoki(key)
    reactionIds.push(emoji)


    const role = emojis[key]
    emojiText += `${emoji} = ${role}\n`

}

firstMessage(client, channelD, emojiText, reactionIds) 

const handleReaction = (reaction, user, add) => {
    if(user.id === '939257079875657758'){
        return
    }

    const emoji = reaction._emoji.name 

    const { guild } = reaction.message
    const roleName = emojis[emoji]
    if (!roleName){
        return
    }


    const role = guild.roles.cache.find(role => role.name === roleName)
    const member = guild.members.cache.find(member => member.id === user.id)

    if (add) {
        member.roles.add(role)
    } else {
        member.roles.remove(role)
    }
}

client.on('messageReactionAdd', (reaction, user) => {
    if (reaction.message.channel.id ===  channelD) {
        handleReaction(reaction, user, true)
    }
})

client.on('messageReactionRemove', (reaction, user) => {
    if (reaction.message.channel.id ===  channelD) {
        handleReaction(reaction, user, false)
    }
})

}