can't get heroku to find my custom module in node.js - node.js

Question

I'm developing an API in node.js that's deployed to heroku, that uses a custom module to fetch weather information from another API.
Here is the App Tree
Here is my app.js
const data_lluvias = require('./data_lluvias');
...
app.post('/aguas_lluvia', (req, res) => {
let data = data_lluvias.getDataLluvias;
res.json(data);
});
app.listen(port, () => {
console.log('Server running');
});
This is the weather module
const url = 'https://climatologia.meteochile.gob.cl/application/productos/boletinClimatologicoDiario';
const getDataLluvias = async () => {
const response = await fetch(url, {
method: "GET",
headers: {
Accept: "application/json",
"Content-Type": "application/json",
},
});
const data = response.json();
return data;
};
module.exports = {
getDataLluvias
};
I can't get heroku to find the module that is in the same folder that my app.js file
Here's the console log
2022-07-16T02:56:32.844556+00:00 heroku[web.1]: State changed from crashed to starting
2022-07-16T02:56:34.518501+00:00 heroku[web.1]: Starting process with command `npm start`
2022-07-16T02:56:36.166569+00:00 app[web.1]:
2022-07-16T02:56:36.166608+00:00 app[web.1]: > conectamilk-npurin#1.0.0 start
2022-07-16T02:56:36.166610+00:00 app[web.1]: > node app.js
2022-07-16T02:56:36.166610+00:00 app[web.1]:
2022-07-16T02:56:36.324024+00:00 app[web.1]: node:internal/modules/cjs/loader:936
2022-07-16T02:56:36.324025+00:00 app[web.1]: throw err;
2022-07-16T02:56:36.324026+00:00 app[web.1]: ^
2022-07-16T02:56:36.324026+00:00 app[web.1]:
2022-07-16T02:56:36.324026+00:00 app[web.1]: Error: Cannot find module './data_lluvias'
2022-07-16T02:56:36.324027+00:00 app[web.1]: Require stack:
2022-07-16T02:56:36.324027+00:00 app[web.1]: - /app/app.js
2022-07-16T02:56:36.324042+00:00 app[web.1]: at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
2022-07-16T02:56:36.324044+00:00 app[web.1]: at Function.Module._load (node:internal/modules/cjs/loader:778:27)
2022-07-16T02:56:36.324044+00:00 app[web.1]: at Module.require (node:internal/modules/cjs/loader:1005:19)
2022-07-16T02:56:36.324044+00:00 app[web.1]: at require (node:internal/modules/cjs/helpers:102:18)
2022-07-16T02:56:36.324045+00:00 app[web.1]: at Object.<anonymous> (/app/app.js:6:22)
2022-07-16T02:56:36.324045+00:00 app[web.1]: at Module._compile (node:internal/modules/cjs/loader:1105:14)
2022-07-16T02:56:36.324045+00:00 app[web.1]: at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
2022-07-16T02:56:36.324046+00:00 app[web.1]: at Module.load (node:internal/modules/cjs/loader:981:32)
2022-07-16T02:56:36.324046+00:00 app[web.1]: at Function.Module._load (node:internal/modules/cjs/loader:822:12)
2022-07-16T02:56:36.324046+00:00 app[web.1]: at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:77:12) {
2022-07-16T02:56:36.324047+00:00 app[web.1]: code: 'MODULE_NOT_FOUND',
2022-07-16T02:56:36.324047+00:00 app[web.1]: requireStack: [ '/app/app.js' ]
2022-07-16T02:56:36.324047+00:00 app[web.1]: }
2022-07-16T02:56:36.449409+00:00 heroku[web.1]: Process exited with status 1
2022-07-16T02:56:36.545505+00:00 heroku[web.1]: State changed from starting to crashed
2022-07-16T02:56:36.550346+00:00 heroku[web.1]: State changed from crashed to starting
I've been trying different paths in the require but none worked.
Can anyone point me the right direction please?
Thanks