Omarchy OS: How do I change the terminal font size?
Use Omarchy’s text-size control for a coordinated change, or edit your terminal’s own configuration.
The display panel has text-size controls. In a terminal, omarchy display text size 14 adjusts the shell, GTK apps, and terminal together; the allowed size is 9–20. Foot applies changes to new windows, so reopen it after the change.
Source: Omarchy manual.