Aktualizacja Flutter SDK
$ flutter upgrade
Zaw Xtut
$ flutter upgrade
//changing to any channel you want before upgrade
//for dev channel
$ flutter channel dev
//for beta channel
$ flutter channel beta
//for stable channel
$ flutter channel stable
//then run this
$ flutter upgrade
// but incase the upgrade does not work, use this
// but make sure you push all your code to what ever online repo
// you are using
flutter upgrade --force