@bahnasawy From our FAQ https://www.databricks.com/learn/certification/faq#certifications-scoring

You are welcome to reregister and retake the exam after 14 days. You can retake the exam as many times as you would like, but you have to wait 14 days between each take. Each attempt is charged at the same price as the original exam. Databricks does not issue free retake vouchers.