You can follow these steps to download your certificate usually within 24 hours of passing your exam.
If you still have not received your certificate yet after a few days, submit a request here. This may be due to a different email being used for the exam to the one on your training account.
If you have taken an exam in Webassessor recently, please allow 10 days for your certificate to show on your training.mulesoft.com dashboard. If the certification still does not appear on your account, please let us know and share a screenshot of your My Learnings section.