@Question12That email is the AOR. You didn't have to wait for it, you could've sent in the work permit application with your sponsorship application and it would've gone faster. You can apply right away, make sure to pick the OPEN work permit.
As other people said, you can apply online. But I believe it will still take 2-3 months.
@koko01
Have you received your OWP? It seems that it has been more than a week after your AoR.