Hikvision removed many legacy firmwares from their main global portal. Try these official channels:
Before downloading any firmware, physically check the camera label. You must identify two things: ds-2cd1021-i firmware download
Updates ensure the camera continues to work seamlessly with the latest versions of Hik-Connect or iVMS-4200 software. How to Safely Download and Update Firmware - Download - Hikvision Europe Hikvision removed many legacy firmwares from their main