Status 302 - missing params in http

[sanetro]

Step 1

public function read(Request $r) {
        if (session()->has('user') == null)
            return redirect()->route('welcome');
    
        if (session()->get('user')) {   
            $groupBelongsToSubject = SylabusToContent::where('sylabus_id', $r->id)
                ->pluck('subject_contents_id')
                ->toArray();
            $contents = SubjectContent::whereIn('id', $groupBelongsToSubject)->get();
            
            return view("content-sylabus", [
                'email' =>              session()->get('user')['email'],
                'role' =>               session()->get('user')['role'],
                'department' =>         session()->get('user')['department'],
                'contents'=>            $contents,
                'code' =>               $r->code,
                'id' =>                 $r->id,
            ]);
        } else {
            return redirect()->back();
        }
    }

Step 2

public function edit(Request $r) {
                
        if (session()->has('user') == null)
            return redirect()->route('welcome');
    
        if (session()->get('user')) 
        {   
            $content = SubjectContent::find($r->id);
            return view("edit-content-sylabus", [
                'email' =>              session()->get('user')['email'],
                'role' =>               session()->get('user')['role'],
                'department' =>         session()->get('user')['department'],
                'content'=>             $content,
                'id' =>                 $r->id,
                'code' =>               $r->code
            ]);
        } else {
            return redirect()->back();
        }
    }

Step 3

public function update(Request $r) {
        $suply = SubjectContent::where('id', $r->id)
            ->update([
                'type_of_content' =>                                     $r->input('type_of_content'),
                'content_description' =>                                 $r->input('content_description'),
                'tags' =>                                                $r->input('tags'),
                'difficulty_level' =>                                    $r->input('difficulty_level'),
                'method_of_veryfication_for_evaluation_of_lecturer' =>   $r->input('method_of_veryfication_for_evaluation_of_lecturer'),
                'method_of_veryfication_for_evaluation_of_exercise' =>   $r->input('method_of_veryfication_for_evaluation_of_exercise'),
                'method_of_veryfication_for_evaluation_of_seminars' =>   $r->input('method_of_veryfication_for_evaluation_of_seminars'),
            ]);
            // not working
            return redirect()->route('readContent', ['code' => $r->code, 'id' => $r->id, 'flag'=>0]);
        }

Redirecting us to this page again and there are no datas