Essential PH-1, Liquid Remix ROM api 28, not rooted, no Gapps, bootloader unlocked. Problem: current slot A, where the ROM boots from, does not have custom recovery installed. However TWRP is installed on slot B. I boot to recovery on slot B but I have no computer, all that's available is a Sony Xperia E5306 C4 on 6.0 not rooted. Do you need another device to execute the command? What are my options?