This article is a new version of upgrading to Postgresql 11 in Debian Stretch, just upgrading content to latest version.
PostgreSQL has taken an enormous lap in last years, not only in features, but in performance and modules, in several cases we have no hurry to upgrading 12 while there is LTS. In many other cases we might want to next latest features, we will walk you thhrough the update procedure in Debian to reach release 13, these steps will be sufficient for any mayor release upgrade.