you can put these commands direclty on ur terminal everytime u use flutter it works smoothly
$Env:NO_PROXY="127.0.0.1,localhost,::1"
$Env:https_proxy="http://<username>:<passowrd>@<domain name>:<port number>"
$Env:http_proxy="http://<username>:<passowrd>@<domain name>:<port number>"