R Package Modification

A package that only works with a built-in dataset would be extremely rare and most likely useless. Packages implement functions that can be executed over input data provided by the user, they usually include some sample data (built-in data) as a mean of easy demonstration of their functionality but they are not limited to work with that particular data.

We don't really have enough information to help you, to help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this guide, to see how to create one: