You need to contact your certifying agency directly–in this case ACE.
www.acefitness.org. Or, (888) 825-3636.
You really need to log into your account at ACE or which ever organization you are certified through for that information. You can call them as well. Most organizations have good customer service. They will walk you through the process. It isn’t all that difficult.
Did you accumulate enough CECs to renew? Do you have your CPR certification up to date? All of the different groups require these things to renew.