To get a yoga Alliance certificate, you have to complete two things.
Finish the 200 hours training with a yoga partnership enrolled yoga teacher training school Rishikesh (Please note, you need to take the course from a school of repute to not only ensure quality training but the school should have a proven track record. If the school does not renew their affiliation in future, your certificate will not be of any use, as you have to search for a registered school on the yoga alliance portal at the time of registration.
Register as soon as you finish the training, there is a sure expense that you have to pay to Yoga Alliance for the enrollment and you need to reestablish the enlistment consistently. It would be ideal if you ensure you enroll on time and reestablish the application consistently.
Hope that helps!!