How do I set a node module import path as a variable?

I have 2 seperate files with various JS functions on them. I want to import either one based on a condition. I am unsure how to do this.

I have:

import { mainURL } from '../../support/helperFunctions.js';

let dataPath = '../../../data/data.js';
if (mainURL.includes('dev')) {
    dataPath = '../../../data/dataDev.js';
}
import { coreData, lastUpdated } from dataPath;

But I get the error Unexpected token for the import line.

I’ve also tried

if (mainURL.includes('dev')) {
    import { coreData, lastUpdated } from '../../../data/dataDev.js';
}
else {
    import { coreData, lastUpdated } from '../../../data/data.js';
}

And a few other variations of this.

Would anyone know how to achieve this in node?