How to declare optional package dependencies?

Hi,

I created a package for a VPN networking tool.
But I noticed that selecting feature in the "make menuconfig" menu does not select the dependencies.

For example, this line does not select the libsqlite3 package when the feature is selected:

ifeq ($(CONFIG_ZEROTIER_ENABLE_NETWORK_CONTROLLER),y)
MAKE_FLAGS += ZT_ENABLE_NETWORK_CONTROLLER=1
DEPENDS+=+sqlite
endif

Source: https://github.com/mwarning/zerotier-openwrt/blob/master/zerotier/Makefile

Maybe someone can point me into the correct direction.