default or selected kernelversion does not have config value CONFIG_DIGIEPCA.
Result is shown for kernelversion 5.6.18

Digiboard Intelligent Async Support

modulename: epca.ko


Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>Digiboard Intelligent Async Support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This is a driver for Digi International's Xx, Xeve, and Xem series
of cards which provide multiple serial ports. You would need
something like this to connect more than two modems to your Linux
box, for instance in order to become a dial-in server. This driver
supports the original PC (ISA) boards as well as PCI, and EISA. If
you have a card like this, say Y here and read the file

To compile this driver as a module, choose M here: the
module will be called epca.

source code: