Need 64 bit version of resource_tool

Running Ubuntu 16.04 LTS VM on Windows 10. Following instructions at: https://www.96boards.org/documentation/consumer/rock/build/aosp.md.html to build AOSP, but fails with error below as “resource_tool” is 32 bit and I need a 64 bit version to run in my VM. Any pointers to where I can download a 64 bit version of “resource_tool” ? Thanks!!!

LD [M] drivers/net/wireless/rockchip_wlan/rtl8723cs/8723cs.ko
LD [M] drivers/net/wireless/rockchip_wlan/rtl8822be/8822be.ko
./scripts/resource_tool: 1: ./scripts/resource_tool: ELFȑ4]: not found
./scripts/resource_tool: 2: ./scripts/resource_tool: Syntax error: “(” unexpected
arch/arm64/Makefile:176: recipe for target ‘rk3399-rock960-model-c.img’ failed
make: *** [rk3399-rock960-model-c.img] Error 2