yarn add @axia-core/txwrapper-axia-core

In a JS/TS index file of package:

import { methods as axia_coreMethods } from '@axia-core/txwrapper-axia-core';

// Export methods of axia-core pallets included in the chain's runtime.
export const methods = {
    balances: axia_coreMethods.balances,
    utility: axia_coreMethods.utility,
    proxy: axia_coreMethods.proxy,
  };

Have a look at the txwrapper creation guide for chain builders to see more guidance on how to use this package in a chain specific txwrapper.