I Dont Have Table User,how To Deal Admin Login In Backend

after installed yii2.0,i start to build my backend scripts,admin login scripts.

But i dont have the table user,and my project dont support user register .

I want to know how to modify this part

struct of the table admin

when i click the submit button,the POST and GET:

run "init" in root application

Run yii migrate after configuring DB connection. It will create the table.