why is i got error eventhough is is the same file type using laravel but in the validation?

public function upload(Request $request)
{

        date_default_timezone_set('Asia/Jakarta');
        $user = Auth::user();

        $validation = Validator::make($request->all(), [
            'file' => 'mimes:jpeg,bmp,png,svg,pdf',
        ]);



        if ($validation->validated()) {



            $file = $request->file('file');
            $input['filename'] = rand() . '.' . $file->getClientOriginalExtension();

            $destinationPath = 'assets/img_po';
            $destinationPathpdf = 'assets/pdf_po';

            $img = Image::make($file->getRealPath());
            $img->resize(400, 400, function ($constraint) {
                $constraint->aspectRatio();
            })->save($destinationPath . '/' . $input['filename']);




            return response()->json([
                'message'  => 'Upload Anda Tersimpan',
                'icon' => 'success',
                'name' => $input['filename'],
                'status' => '1',
            ]);
        } else {

            return response()->json([
                'message' => $validation->errors()->all(),
                'icon' => 'error',
                'status' => '0',
            ]);
        }
    }

<——- html form——–>

File PO :

        <input type="hidden" class="isi" id="filepo">
        <div id="gambar">
          <div onclick="$('#uploadpo').click();">
              <button class="btn btn-primary">
                <span class="tf-icons bx bx-upload"></span>&nbsp; Upload PO
              </button>
          </div>
          <input id="uploadpo" name="file" type="file" style="display:none;" multiple/>
        </div>

<————–the javascript————->

$(“#uploadpo”).on(“change”, function() {

$(‘.loading’).attr(‘style’,’display: block’);

var formData = new FormData();
formData.append(‘file’, $(‘#uploadpo’)[0].files[0]);

$.ajax({
url: “{{ route(‘po.upload’) }}”,
method:”GET”,
data: formData,
headers: {
‘X-CSRF-TOKEN’: $(‘meta[name=”csrf-token”]’).attr(‘content’)
},
dataType:’JSON’,
contentType: false,
cache: false,
processData: false,

  success:function(data) {

    $('.loading').attr('style','display: none');

      if(data.status == '1'){

        $("#filepo").val(data.name);

        $('#gambar').html("<button class='btn btn-success'><span class='tf-icons bx bx-check'></span>&nbsp; PO Sudah Terupload</button>")

          swal({
              title: "Berhasil!",
              text: "Upload Berhasil!",
              icon: "success",
              buttons: false,
              timer: 2000,
          });

      } else {

          swal({
              title: "Gagal!",
              text: "Pastikan File yang Anda Upload Benar!",
              icon: "error",
              buttons: false,
              timer: 2000,
          });


      }
  }

});

});

<————-route————>

Route::get(‘/po/add’, [AppHttpControllersPOController::class, ‘add’])->name(‘po.add’);

Route::get(‘/po/upload’, [AppHttpControllersPOController::class, ‘upload’])->name(‘po.upload’);