https://online.stanford.edu/programs/product-management-program
might be good certification from Stanford University
or getting PSPO (Professional Scrum Product Owner) from Scrum.org
for prep: https://www.linkedin.com/learning/professional-scrum-product-owner-i-pspo-i-cert-prep/course-welcome
10 hours of content
or just finish AHA course from linkedin: https://www.linkedin.com/learning/paths/aha-product-management-professional-certificate
Good interview prep watclist at youtube
https://www.youtube.com/playlist?list=PLTjcBkvRBqGFBklqNYJoWyCV0xVMrhEeL