How to use exported symbol on another kernel module?

I've two kernel modules A and B, the module A exports the function foo using EXPORT_SYMBOL(foo). To be sure if the symbol was correctly exported I executed cat /proc/kallsyms | grep foo which gives me the following:

0000000000000000 r __ksymtab_foo       [mod_a]0000000000000000 r __kstrtab_foo       [mod_a]0000000000000000 T foo [mod_a]

I want to use the function foo on module B, in order to do it I build the module B with the following Makefile

KBUILD_EXTRA_SYMBOLS := /path/to/mod/a/Module.symversobj-m = mod_b.o# Get the current kernel version numberKVERSION = $(shell uname -r)all:    make -C /lib/modules/$(KVERSION)/build M=$(PWD) modulesclean:    make -C /lib/modules/$(KVERSION)/build M=$(PWD) clean

But even using KBUILD_EXTRA_SYMBOLS I receive a error: implicit declaration of function ‘foo’ when I try to build the module B. Am I using the KBUILD_EXTRA_SYMBOLS right? Btw, build the two modules together isn't an option.

My kernel version is 5.4.0