cloudNativePg bootstrap from dump

Hi

[I'm not sure if cloudNativePg questions are suitable for this list, let me
know if not...]

I'd like to bootstrap a Cluster in CNPG from a PostgreSQL dump but I'm not
sure it can be done and in case how.
Docs show 3 options: 1. initdb,2. pg_basebackup and 3. recovery
Initdb seems the correct one to me and I could just start an empty db and
psql data into it.
When I do that data seem to to get in but the psql process never ends:

kubectl cnpg psql my-db < dump.sql

As a second option I'd like to know how to bake a backup from a Postgres
instance suitable for the 'recovery' option.
If I understand this options would require me to stick to the same
PostgreSQL version/

If I backup a db (kubectl cnpg backup) I get a directory with data.tar.gz
(the physical backup) and a JSON file that describes it.
I guess the data are produced by pg_basebackup, bu how should I produce the
json description?

sandro