In order to have an active account with DMCA.com you need to purchase a Protection Pro subscription. You can do so here: https://www.dmca.com/Toolkit/signup.aspx
If you have paid and your account is still showing inactive please log out and back in, in order to see the active status. If you are still showing inactive please send us a question within your account and we will look into this: https://www.dmca.com/Questions.aspx