Shadowblitz16 connect to mailcow over libre wolf browser
use pop3 to move mail to kmail and allow me to send mail with kmail?
KMail and LibreWolf do not require any special server-side configuration to work with Mailcow. The former is simply an IMAP/POP3 email client, and the latter is just a web browser.
If you follow the Mailcow documentation and set-up your DNS records correctly, Mailcow should work with LibreWolf and KMail just as it does with most other browsers and email clients.
If you actually do run into issues that are specific to KMail or LibreWolf while everything works fine with other email clients or browsers, then the problem is most likely on the client side and not something that can be solved through server-side configuration.