I have list of command's and output, is there a e-mail where I can send my steps.
If I put it in here I get a screen saying you are been blocked.

The problem is:
┌──(kali㉿kali)-[~]
└─$ sudo gvm-setup -h

[>] Starting PostgreSQL service
[-] ERROR: The default PostgreSQL version (15) is not 16 that is required by libgvmd
[-] ERROR: Use pg_upgradecluster to update your PostgreSQL cluster

Have you upgraded your postgresql cluster like it is saying?

I have a step by step commands based on the error with output.
But it is to large to place it here. And Yes I did.

What commands did you run to upgrade your cluster? What was the output?

sudo gvm-setup -h

[>] Starting PostgreSQL service
[-] ERROR: The default PostgreSQL version (15) is not 16 that is required by libgvmd
[-] ERROR: Use pg_upgradecluster to update your PostgreSQL cluster

sudo pg_lsclusters

sudo pg_dropcluster --stop 16 main

sudo pg_upgradecluster 15 main
Stopping old cluster...
Restarting old cluster with restricted connections...
Notice: extra pg_ctl/postgres options given, bypassing systemctl for start operation
Creating new PostgreSQL cluster 16/main ...
/usr/lib/postgresql/16/bin/initdb -D /var/lib/postgresql/16/main --auth-local peer --auth-host scram-sha-256 --no-instructions --encoding UTF8 --lc-collate en_US.UTF-8 --lc-ctype en_US.UTF-8 --locale-provider libc
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.

The database cluster will be initialized with locale "en_US.UTF-8".
The default text search configuration will be set to "english".

Data page checksums are disabled.

fixing permissions on existing directory /var/lib/postgresql/16/main ... ok
creating subdirectories ... ok
selecting dynamic shared memory implementation ... posix
selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting default time zone ... US/Eastern
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok

Copying old configuration files...
Copying old start.conf...
Copying old pg_ctl.conf...
Starting new cluster...
Notice: extra pg_ctl/postgres options given, bypassing systemctl for start operation
Roles, databases, schemas, ACLs...
set_config

(1 row)

set_config

(1 row)

Fixing hardcoded library paths for stored procedures...
Upgrading database template1...
Analyzing database template1...
Fixing hardcoded library paths for stored procedures...
Upgrading database postgres...
Analyzing database postgres...
Stopping target cluster...
Stopping old cluster...
Disabling automatic startup of old cluster...
Starting upgraded cluster on port 5432...

Success. Please check that the upgraded cluster works. If it does,
you can remove the old cluster with
pg_dropcluster 15 main

[] Checking Default scanner
[] Modifying Default Scanner
Scanner modified.

[+] Done
[] Please note the password for the admin user
[] User created with password '****'.

[>] You can now run gvm-check-setup to make sure everything is correctly configured

sudo gvm-check-setup -h

Step 9: Checking greenbone-security-assistant...
OK: greenbone-security-assistant is installed

So, maybe you could update 2023.3 to 2023.4 where error 'The default PostgreSQL version (15) is not 16' is resolved prior running 'gvm-setup -h'.

I'm not sure what you mean by your last statement; that error message comes from postgres, not from gvm.

If you follow the response flow, I will see that the last statement applies to 0018564. This error comes from gvm-setup.
That's why I said "you could update 2023.3 to 2023.4 where error 'The default PostgreSQL version (15) is not 16' is resolved prior running 'gvm-setup -h'." For example, install only version 16 and not 15.
I just suggestion/idea.

the gvm.sh script, is simply a script, it is running commands and showing the output. The output that is shown where it has this "error" is from postgres and not gvm. But yes, if a user upgrades postgres, they are expected to upgrade the clusters; there is an entire message that pops up during the upgrade that explains this to the users. I am going to close the bug, because it's not an actual bug, it was simply that the postgresql upgrade process hadn't been followed.

I do not agree with your conclusion, this is a problem in Kali Linux 2023.3 using old PostgreSQL version without upgrade command to update the VM after starting the first time.
$ sudo update
$ sudo upgrade

My advice at least is to update the installation process on 'https://www.kali.org/tools/gvm/' with the following commands:
$ sudo pg_lsclusters
$ sudo pg_dropcluster --stop 16 main
$ sudo pg_upgradecluster 15 main
$ sudo pg_lsclusters

You can disagree all you like, but we do not put out new releases every time an update happens and users don't follow the documentation that the package update provides.

Once the system is installed, it is on you, the end user, to follow the instructions in keeping it up to date. Adding in the instructions for 15-16, means keeping it up to date when 17 comes out, and then 18, and then 19, and that is extra work for no benefit. It already tells you when the update comes that you need to upgrade the cluster.

This is not a bug, this is how software updates work.