i was coding my welcome message on my discord bot, but when someone enters in the server, console give me this error:

TypeError: Cannot read properties of undefined (reading 'cache')

here is my guildMemberAdd.js code:

const { MessageEmbed } = require('discord.js');

module.exports = {
name: "guildMemberAdd",
execute(member) {
    const MemberRole = member.guild.roles.cache.get('891716789879316540');
    member.roles.add(MemberRole);
    
    const WelcomeEmbed = new MessageEmbed()
    .setColor('RANDOM')
    .setAuthor('WELCOME', member.user.displayAvatarURL({dynamic: true}))
    .setDescription(`Welcome ${member} in our server!\n you are the number ${member.guild.memberCount}`)
    .setFooter(`${member.user.tag}`, member.user.displayAvatarURL({dynamic: true}))
    .setTimestamp();
    member.guild.channel.cache.get('768526997882142743').send({content: `${member}`, embeds: [WelcomeEmbed]});

    const LogEmbed = new MessageEmbed()
    .setColor('GREEN')
    .setDescription(`${member} came in our server`)
    .setTimestamp();

    member.guild.channel.cache.get('768526997882142743').send({embeds: [LogEmbed]});
    }
}

the strange thing is that on the 6th line it works fine, but in the 15th line and in the 22th doesn't works