A budget Realme phone, released August 14th, 2020. It packs a 6.5" 720p IPS screen, a Helio G35 chipset, and up to 64GB of storage. It also features a third 2MP camera and fingerprint sensor, which are absent in Realme C11.
Try backing up your phone onto a laptop or a p.c anywhere just back it up. Then factory reset your phone. If camera still doesn’t work, then either the connector has come loose or camera has failed.