unrooting lineageos 21 poco x3 nfc surya

i m new to flashing roms and these things so i choosed lineage os as my first rom cuz its offical and i like that actually and there is big community for it so thanks for that

first problem i got and the only one i met actually is whatsapp

i rooted the phone without knowing that this will happen i saw alot of nice mods and these things so i rooted it now i want whatsapp to work ,, i got alot of work on it and groups and important things i need to be up-to-date in these things

so if there a way to install whatsapp on the rooted phone please tell me
or if there is a way to unroot the phone that would be good also "without formating the data"

sry if my english was bad i m actually arab so yea thank u and happy new year !