Do android roms with only boot.img file available in fast boot rom don’t have separate recovery.img

I have phone named **Vivo Y83 /(vivo1802)** I wanted the stock recovery image of my device to port twrp recovery since it’s not officially available for my device. But after getting hands on my fastboot rom…. There is only boot.img present in rom So my question is is the recovery image is part of boot image in my rom? And if yes….how would I proceed to build twrp for myself?