For a custom device that doesn't have the traditional phone buttons and no screen, is there a way to determine the button sequence to enter bootloader? I've seen the article howtogeek.com/249439/how-to-enter-androids-bootloader-and-recovery-environments/ which lists different manufacturers however I'm curious if there is a definition in the firmware itself.
For a small detail there are references that Xiaomi was used as the base for this custom firmware however since it's not a Xiaomi phone I don't want to button mash combinations and brick the device.