You CANNOT Be a True ScrumMaster With a Certificate Alone
ScrumMasters need to master Scrum - According to the Scrum Guide, a Scrum Master is accountable for two things:
“The Scrum Master is accountable for establishing Scrum as defined in the Scrum Guide. They do this by helping everyone understand Scrum theory and practice, both within the Scrum Team and the organization.” — Scrum Guide 2020
“The Scrum Master is accountable for the Scrum Team’s effectiveness. They do this by enabling the Scrum Team to improve its practices, within the Scrum framework.” — Scrum Guide 2020
To be able to help people understand Scrum, you need to have a solid understanding of Scrum yourself. The same can be said about the accountability for the team’s effectiveness working with Scrum.