I am setting up Barman 3.11.1 and PostgreSQL 12.20 on the same Ubuntu machine Ubuntu 22.04.4 LTS. I would like to take file-level incremental backups using Barman. I am encountering errors while executing a full backup.

Here’s what I’ve done so far:

1. Installed both Barman and PostgreSQL 12 on the same machine.
2. Configured Barman for file-level incremental backups.
3. Verified that the PostgreSQL database is running and accessible.
4. Checked permissions on the Barman directories and made sure the Barman user has the
   required access.
5. Ran the “barman check ” command

I am getting the following errors:

1. WAL archive: FAILED (please make sure WAL shipping is setup)
2. archiver errors: FAILED (unknown: 1)

When i execute the command “barman backup ” then in am getting the error as :

ERROR: Impossible to start the backup. Check the log for more details,
or run ‘barman check ‘

So , I have checked the PostgreSQL logs and i found there are no errors logged in it. Additionally, i have check the barman logs and found the following error logged in it

barman.server ERROR: Check ‘WAL archive’ failed for server

What are the common steps I might have missed to allow Barman to perform file-level incremental backups on the same machine?