CI4 in localhost

hi , sorry for english im new in ci4 , in ci3 when i unzip the project in my localhost i can access by the browser visit the url http://localhost/myproject , now in ci4 i must add at the url the public http://localhost/myproject/public  but i have the error 

Code:

[color=#333333][size=small][font=Tahoma, Verdana, Arial, sans-serif][color=#222222][size=xx-large]Whoops![/size][/color]

[color=#777777][size=large]We seem to have hit a snag. Please try again later...[/size][/color][/font][/size][/color]

my .env is in development mode .

If i run the command php spark serve it work fine , Why ?