Head to orderstate.com and click Go to app at the top right corner. It will redirect you to app.orderstate.com where you can click Sign In in the top-right corner. Put your username and password and you will log into your account. You'll see all the orders you have access to here.
If you don't have access to Orderstate yet, click on Sign Up button and create an account. You can find more details here.
Signing out of Orderstate
To sign out of Orderstate, click your picture in the upper-right corner at orderstate.comand scroll down to Sign Out.