Invoke lambda from another service node.js

Help please! What is the correct flow for importing another lambda from a different service?

If I import the function using require I can run it locally, but when I package and deploy I get a ImportModuleError.

I have tried importing as a local npm module using npm init on the function I want to invoke, and then requiring the module just like a normal npm package, but I still get ImportModuleError in the cloud when I invoke it.

I know it is possible to hook up the function using API gateway, but on these forums I saw people saying how direct invocation of lambda functions is also possible and cheaper. Please help me out