Laravel 6: 2 buttons in one form performing different functions - laravel

Question

I have a form with 2 buttons, 1 button saves the changes to the form to a db(including the filename in the field named "attachment", the second button uploads the actual file to the server.
I was able to have each button echo save or upload depending on the press, so the form reads which button is pressed and the save function also works. However the the upload function doesn't seem to read the input field named "attachment"
I am using 1 controller with three functions. The html code for the buttons is:
<input type="file" name="attachment" enctype="multipart/form-data"/>
<p align="center">
<input type="submit" btn btn-primary class="btn btn-primary" id="upload" name="action" value="upload">
<input type="submit" btn btn-primary class="btn btn-primary" id="save" name="action" value="save">
The controller has 3 functions, one overall function which calls either the update or upload function, one that saves the changes, one that is supposed to upload the file
Overall:
public function store(Request $request, $_id = false, $attachment = false){
//check which submit was clicked on
if($request->action == 'upload'){
//
$this->upload($request);
return redirect()->route('home');
} elseif($request->action == 'save') {
//echo 'save pressed';
//run function save all form fields
$this->update($request, $_id);
return redirect()->route('home');
} else {echo "error";}
}
Save changes: (the one that works)
public function update (Request $request, $_id){
//$this->upload($request);
/*
$path = $request->file('attachment');
$path->storeas('/public','123'); */
$data = post::findOrFail($_id);
$data->title = $request->title;
$data->content = $request->content;
$data->shorttext = $request->shorttext;
$data->created_by = $request->created_by;
$data->text3 = $request->text3;
$data->attachment = $request->attachment;
$data->save();
/* return response()->json([
'name' => 'Abigail',
'state' => 'CA'
]); */
if($data){
return redirect()->route('home');
}else{
return back();
}
}
Upload:
function upload(Request $request){
$path = $request->file('attachment');
// $original = $request->file('attachment')->getClientOriginalName();
$path->store('/public');
//return $original;
}
Upload gives an error: Call to a member function store() on null
I think this means it cannot read the field "attachment" therefore it returns null and cant upload anything. Maybe this has something to do with the fact the from uses #put and the upload needs post?
I have tested the upload function itself in a separate blade and a separate controller and there it works but as i said the method is post in that case.
For completeness the routes to my form and my separate upload test bewlo (any help is much appreciated (I would love to have both functions on 1 button, so i coud press the button and it uploads a file, saves the changes and stores the filename in the DB , but I will settle for 2 buttons for now.
Route::put('/post/update/{_id}', 'PostController#store')->name('post.update');
//test for upload only
Route::post('/upload', "UploadController#upload")->name('upload');