ICIDU Wireless Router 150N (NI-707517)
Not officially supported yet, however this router is a clone of the supported TP-LINK TL-WR741ND v1 for which compatible modified firmware exist on the DD-WRT forum to cross flash it from ICIDU to TP-LINK brand. After crossflash you can flash original OpenWrt 18.06.5 firmware and follow instructions for the TP-LINK TL-WR741ND v1.
From the DD-WRT forum you can find details to prepare and or get a modified TP-LINK WR741ND v1 firmware, see forumuser botterbloem's post with “v1.bin” attachment. You may have to login to get that firmware file!
#md5/sha256 for crossflash firmware 8c891f44eb243120f0443e5d942139c9 v1.bin ea5adafc6c736483341282af806368f8dc305706a76c6c76466fa874b30eb567 v1.bin
From the stock ICIDU Firmware webinterface 3.10.1(Build 100112 Rel.36305n) goto “System Tools” and do a firmware upgrade with “v1.bin” firmware file. After flash to the TP-LINK firmware 3.12.4 (Build 100910 Rel.57694n), continue install to OpenWrt using original wr741nd-v1 instructions. No need to alter/hexedit the OpenWrt firmware images.