NEED HELP: C#

Please I am a Beginner in C# and I need little help with Methods.

In the Picture attached, I'd love to use User input as Parameters in the method. Example: example getting user imput with Console.ReadLine(); and storing it to num1 or num2 as parameter in the Method.

Is this possible in C#, if so, how can I make it work? Thanks

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Please look at this code, I wanna know why the $ and {} was added to the alert method to pop up the key and value of user.

what is their functionality there?

let user = {
name: "John",
age: 30
};

// loop over keys-and-values
for (let [key, value] of Object.entries(user)) {
alert(`${key}:${value}`); // name:John, then age:30
}

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I have reinstalled node js 3 times to run JS scripts and "npm run dev" is not starting up the server. This is quite frustrating.

😂😂......if you ever did this raise your hands

I want to make a career in debugging codes, what's the best way to achieve that?