Fix

The error occurs because you are trying to access a Go identifier that starts with a lowercase letter from a different package. In Go, only identifiers starting with an uppercase letter are exported (visible) outside their defining package. To fix this, rename the identifier in the source file to start with an uppercase letter, or move the calling code into the same package as the identifier.

// Before (in package mypkg)
func myPrivateFunction() {} // lowercase 'm' = unexported

// After (in package mypkg)
func MyPublicFunction() {} // uppercase 'M' = exported

// Usage in another package
// mypkg.MyPublicFunction() // Now works

Go uses capitalization to control visibility. Identifiers starting with a lowercase letter are private to their file or package, like a private room in a house. Identifiers starting with an uppercase letter are public, like the front door, allowing other packages to access them. You must capitalize the name to share it.