Problems with Flutter DAP support in Neovim

This was code I am trying to run

  1 return require'dap'.setup{
  2   require'dap'.adapters.dart = {
  3     type = "executable",
  4     command = "deno run",
  5     args = {"/home/alexander/.local/share/nvim/site/pack/packer/start/Dart-Code/src/debug/flutter_run.ts", "flutter"}
  6   }
  7   require'dap'.configurations.dart = {
  8     {
  9       type = "dart",
 10       request = "launch",
 11       name = "Launch flutter",
 12       dartSdkPath = "/home/alexander/flutter-sdk/flutter/bin/cache/dart-sdk",
 13       flutterSdkPath = "/home/alexander/flutter-sdk/flutter",
 14       program = "${workspaceFolder}/lib/main.dart",
 15       cwd = "${workspaceFolder}",
 16     }
 17   }
 18 }

but I have got a lot of errors which I don't understand and they are in my native language which is not English, sorry.