How to find missing ppp commands?

I made my own linux distribution with buildroot. In "make menuconfig" and "make linux-menuconfig" I checked all options related to "ppp" and "pppd". Unfortunately, after building my distribution I can't use the commands "pon", "poff", "plog" and probably others. The system cannot see them. I looked and they are not in "/ usr / bin" or "/ usr / sbin". What could be causing this? I found out somewhere that these are debian-only commands, but how can I enable the pppd daemon?