Steps to follow are described below
Server
1.Open terminal
2.Navigate to project root folder
3.Run “flutter build web”
4.Get full path of working directory using command “readlink -f .”
5. concatenate full path with “/build/web”
6. Upload above concatenated folder to default nginx folder using scp
Command : scp -r path user@ip :/nginx/folder
7. Enter there server via ssh
8. Edit default nginx config file and add web folder to path
9.Restart nginx