Db.set is not a function!

Hi! I am using quick.db, and whenever I do db.set it always works, but in 1 specific file it doesn’t! What wrong?

const Discord = require('discord.js')
const db = require('quick.db')
module.exports.run = async(client, message, args) => {
    if (!message.member.hasPermission("ADMINISTRATOR") || !message.member.hasPermission("MANAGE_CHANNELS") || !message.member.hasPermission("MANAGE_GUILD") || !message.member.hasPermission("MANAGE_MESSAGES")) {
        return message.channel.send("You have insufficient permissions to execute this command!")
    }
    if (!args[0]){
        return message.channel.send("Please say a channel ID!")
    } 
    if (message.guild.channels.get(args[0])) {
        db.set(`autoTextChannelID_${message.guild.id}`, `${args[0]}`)
    }
}

what are your errors?