S24 ultra not receiving updates

[holamsnatty]

Please my s24 ultra is not receiving updates it's unlocked but the service provider is tied to Verizon i stay in Nigeria they said for me to start receiving OTA updates i need to flash a u1with CSC of XAA firmware on it it's currently a u with GCF/VZW model will it start receiving updates after flashing a U1 firmware on it and will it not brick my phone