I have a question about this fiddle:
This works in any local environment, but the question is, how to mask the data or how to encrypt in smaller values.
`pgp_sym_encrypt()` is provided by the extension [pgcrypto](https://www.postgresql.org/docs/current/pgcrypto.html). If it works in your local database, then you have installed the extension there.
You need to install the extension in every environment where you want to use it.
To do that, connect to the database as the superuser (typically `postgres`) then run:
create extension pgcrypto;