default or selected kernelversion does not have config value CONFIG_WANPIPE_FR.
Result is shown for kernelversion 5.4.123

WANPIPE Frame Relay support

configname: CONFIG_WANPIPE_FR

Linux Kernel Configuration
└─>Networking support
└─>Wan interfaces
└─>WANPIPE Frame Relay support
In linux kernel since version 2.6.12  
Connect a WANPIPE card to a Frame Relay network, or use Frame Felay
API to develop custom applications.

Contains the Ethernet Bridging over Frame Relay feature, where
a WANPIPE frame relay link can be directly connected to the Linux
kernel bridge. The Frame Relay option is supported on S514-PCI
and S508-ISA cards.

Say Y and the Frame Relay support will be included in the driver.