Newer 1xx3 and HikLook models have moved to V5.7.21, but legacy DS-2CD1021-I units should strictly follow the R2 platform path unless otherwise noted on the Hikvision Europe Download Portal Step-by-Step Upgrade Procedure How to check the correct FW package - Hikvision
For European models, the Hikvision Europe Portal provides specific R2 platform builds like V5.4.5 . ds-2cd1021-i firmware download
If your camera is working stably, do not update . Only update if you need a specific security patch or bug fix. Newer 1xx3 and HikLook models have moved to V5
The file will be named similar to: IPC_E2_En_V5.5.82_180625.zip . the .dav firmware file. ds-2cd1021-i firmware download