Please see the output from console which is proving the problem:
BusyBox v1.30.1 () built-in shell (ash)
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| |.-----.-----.-----.| | | |.----.| |_
| - || _ | -__| || | | || _|| _|
|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
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OpenWrt 19.07.0, r10860-a3ffeb413b
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root@router:~# opkg update && opkg install zip
Downloading http://downloads.openwrt.org/releases/19.07.0/targets/ramips/mt7621/packages/Packages.gz
Updated list of available packages in /var/opkg-lists/openwrt_core
Downloading http://downloads.openwrt.org/releases/19.07.0/targets/ramips/mt7621/packages/Packages.sig
Signature check passed.
Downloading http://downloads.openwrt.org/releases/19.07.0/targets/ramips/mt7621/kmods/4.14.162-1-2e88863ccdd594fb8e842df3c25842ee/Packages.gz
Updated list of available packages in /var/opkg-lists/openwrt_kmods
Downloading http://downloads.openwrt.org/releases/19.07.0/targets/ramips/mt7621/kmods/4.14.162-1-2e88863ccdd594fb8e842df3c25842ee/Packages.sig
Signature check passed.
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/base/Packages.gz
Updated list of available packages in /var/opkg-lists/openwrt_base
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/base/Packages.sig Signature check passed.
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/luci/Packages.gz
Updated list of available packages in /var/opkg-lists/openwrt_luci
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/luci/Packages.sig
Signature check passed.
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/packages/Packages.gz
Updated list of available packages in /var/opkg-lists/openwrt_packages
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/packages/Packages.sig
Signature check passed.
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/routing/Packages.gz
Updated list of available packages in /var/opkg-lists/openwrt_routing
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/routing/Packages.sig
Signature check passed.
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/telephony/Packages.gz
Updated list of available packages in /var/opkg-lists/openwrt_telephony
Downloading http://downloads.openwrt.org/releases/19.07.0/packages/mipsel_24kc/telephony/Packages.sig
Signature check passed.
Unknown package 'zip'.
Collected errors:
* opkg_install_cmd: Cannot install package zip.
Router can ping 8.8.8.8.
Can anyone check if you can install this package on your router with OpenWrt 19.07.0?