Your firmware can be downloaded from here:
DOWNLOAD EU PORTAL
The notes say:
V3.4.0 build151201 for DS-7104(08) 7204(08) HQHI-F_N
V3.4.1 build151221 for HGHI-E HGHI-F
V3.4.1 build160115 for HGHI-E HGHI-F
V3.4.1 build160422 for HGHI-E HGHI-F
V3.4.2 build160119 for 7104(08)_7200HQHI-F_N
V3.4.3 build160203 for 7204(08)HUHI-F_N
V3.4.4 Build160405 for 71_72HQHI-F_N 7204(08)HUHI-F_N
V3.4.4 Build160511 for 71_72HQHI-F_N 73_8104(08)(16)HQHI-F_N 7204(08)HUHI-F_N
V3.4.50 Build160516 for 7200HUHI-F_N
V3.4.51 Build160607 for 7200HUHI-F_N 7600HUHI-F_N
V3.4.60 build160607 for 73_81_9000HUHI-F_N
V3.4.70_Build160708 for 71_72HQHI-Fx/N, 71_72HGHI-Fx
V3.4.70_Build160729 for 71_72HQHI-Fx/N, 71_72HGHI-Fx
V3.4.75_Build160827 for HQHI-Fx/N, 71_72HGHI-Fx, 72HUHI-Fx/N
V3.4.76_Build160914 for HQHI-Fx/N, 71_72HGHI-Fx, 72HUHI-Fx/N
V3.4.80_Build161217 for all turbo 3.0 DVR,
V3.4.81_Build170227 for all turbo 3.0 DVR,
V3.4.82_Build170427 for all turbo 3.0 DVR,
V3.4.83_Build170526 for all turbo 3.0 DVR,
V3.4.84_Build170626 for all turbo 3.0 DVR,
V3.4.87 build180108 for all turbo 3.0 DVR,
V3.4.88 build 180207for all turbo 3.0 DVR,
V3.4.89 build 180906(For HGHI-F)
v3.4.90_Build170205 for 72HUHI-Fx/S
v3.4.91_Build170405 for 72HUHI-Fx/S
v3.4.92_Build170809 for 72HUHI-Fx/S
Our guide to updating Hikvision firmware is here:
How to update HikVision Firmware in just nine simple steps - updated 30th October 2018