Getting permission denied while running query in azure PostgreSQL flexible server

I have been created a PostgreSQL 16 database on azure flexible server and login with the admin account and trying to use postgresql-anonymizer but while following the doc for Anonymous Dumps by https://postgresql-anonymizer.readthedocs.io/en/stable/anonymous_dumps/
But I was not able to run a query `ALTER ROLE dump_anon SET anon.transparent_dynamic_masking = True;`
It shows `ERROR: permission denied to set parameter "anon.transparent_dynamic_masking"`
what's the issue and how to resolve it?

Requirement: I want to dump masked/anonymized data.