使用clientExtension()而不是getClientOriginalExtension()并确保您的路径正确，在这里我定义了public路径.

use clientExtension() instead of getClientOriginalExtension() and make sure your path is correct here I defined the path of public.

if ($request->hasFile('image')) {
    $file = $request->image;
    $destinationPath = public_path().'/images/';
    $filename= $student->username . '.'.$file->clientExtension();
    $file->move($destinationPath, $filename);
    $student->image=$filename;

}