What do I do with the ".ext?"

[James Moe]

dovecot 2.3.15
opensuse LEAP 15.4

  I am installing dovecot and have postfix as the SMTP agent. It also needs to
use a MySQL database. In </etc/dovecot> there is the main dovecot.conf file, and
a number of other files with the extension ".conf.ext."
  It is not clear how to use these. I could nothing in the documentation that
discusses it.
  Do I copy one, say dovecot-sql.conf.ext, modify it:
- rename the copy without the ".ext?"
- or move the copy to the "conf.d" directory, with or without the "ext?"

-- 
James Moe
moe dot james at sohnen-moe dot com
520.743.3936
Think.