Once you have passed the PL-300 certification exam, rest assured that your official certificate will be available in Microsoft's Certification Dashboard. Below is a guide to help you find it, download it, as well as share it:
Log In to Microsoft's Certification Dashboard: Go to - https://www.microsoft.com/learning/dashboard.aspx and provide the login credentials for the account you utilized to register for the certification exam.
Get Your Certificate: you are expected to see an area indicating 'Certificates' or go to Transcript and Badges. After completing it, you will get an email with the proper certificate and credentials.
You can also check out Edureka's Microsoft Power BI Certification Training: PwC Academy, which will train the learners to pass the PL-300 exam.
I hope the above steps inadvertently help you get your PL-300 certification. Microsoft offers the possibility of further extending your certificate through online networks, which is useful in promoting the certificate.