Slackware64-current upgrade glibc-2.33

I have VBOX Slackware64-current updated until 13.1.2021.
Installed without KDE.
I wish to update it to recent packages.
As slackpkg and slackpkg+ are upgraded, I did that first -successful.
After that I execute:
Quote:

slackpkg install-new

It offers poke-1.0-x86_64-1 and aaa_libraries-15.0-x86_64-3
I've selected both but upgrade failed with
Quote:

/bin/sh: /lib64/libc.so.6: version 'GLIBC_2.33' not found ...

and also nonworking slackpkg (same error):confused:

What is the correct procedure to upgrade my system:
upgrade slackpkg, slackpkg+
glibc
all other