Discord.js Mention, User Undefined

EDIT: I have found the solution by myself, thank you everybody who sees this post! The solution is :

/// SIMPLY ADD || message.member
const taggedUser = message.mentions.members.first() || message.guild.members.cache.get(args[1]) || message.member

That is the solution to this problem, it's not the same as message.author but at least it works now!

Original: I'm having a little problem with my script! Any help would be highly appreciated!

Here's the problem: This is the first script, this script doesn't have any problems in it, it all worked out smoothly, except that this script sends a message instead of changing the let, it would make me create multiple embeds. But in this example, it uses a simple message.send instead

    if(command === 'test'){
/// ALL OF THIS WORKS
        const taggedUser = message.mentions.members.first() || message.guild.members.cache.get(args[1])
        if(!taggedUser){
            if(message.member.roles.cache.has('745227998893965322')){
                message.channel.send('Yes, you have that role #1')
            }else{
                message.channel.send('No, you don\'t have that role #1')
            }
        }
        if(taggedUser.user.id === message.author.id){
            if(message.member.roles.cache.has('745227998893965322')){
                message.channel.send('Yes, you have that role #2')
            }else{
                message.channel.send('No, you don\'t have that role #2')
            }
        }
        if(taggedUser.user.id != message.author.id){
            if(taggedUser.roles.cache.has('745227998893965322')){
                message.channel.send('Yes, that user have that role')
            }else{
                message.channel.send('No, that user doesn\'t have that role')
            }
        }
    }

While in this script in the other hand, it works when mentioning a user, and it works when we mention ourselves. If we didn't add any mention, the log would say that the User is undefined. The reason why i use a let name so i can easily change the text there instead of creating multiple embeds

    if(command === 'test2'){
        const taggedUser = message.mentions.members.first() || message.guild.members.cache.get(args[1])

        let name
        if(!taggedUser){ /// THE PROBLEM IS RIGHT HERE, WHEN NO MENTION, USER IS UNDEFINED
            if(message.member.roles.cache.has('745227998893965322')){
                name = 'Yes, you have that role #1'
            }else{
                name = 'No, you don\'t have that role #1'
            }
        }
/// THE REST OF THIS WORKS FOR SOME REASON
        if(taggedUser.user.id === message.author.id){
            if(message.member.roles.cache.has('745227998893965322')){
                name = 'Yes, you have that role #2'
            }else{
                name = 'No, you don\'t have that role #2'
            }
        }
        if(taggedUser.user.id != message.author.id){
            if(taggedUser.roles.cache.has('745227998893965322')){
                name = 'Yes, that user have that role'
            }else{
                name = 'No, that user doesn\'t have that role'
            }
        }

        message.channel.send(`${name}`)
    }

Is there any solution to this? I have tried a different method but it just gives me multiple new errors. Thank you for reading this