Js can't read the .value property for an input. Why?

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Javascript

i have an input from html file.
and i have an js file.

but when i hit the "Submit" button, there's a error. why?

the code:

html:

<form method="" action="">
<input autofocus type="text" name="mission" id="mission" class="" placeholder="" required >
<label id="" for="mission"> name: </label>

<button id="submit" type="submit">submit</button>

</form>

js:

var button = document.querySelector("#submit");

	button.addEventListener("click", function(){
	var firstAns = document.getElementById("#mission").value;
	console.log(firstAns);  //there's an error

});

What I have tried:

read some articles but i have got nothing.