Call to a member function move() on string
if ($request->hasFile('file')) {
$destinationPath = 'path/th/save/file/';
$files = $request->file('file'); // will get all files
foreach ($files as $file) {//this statement will loop through all files.
$file_name = $file->getClientOriginalName(); //Get file original name
$file->move($destinationPath , $file_name); // move files to destination folder
}
}