How are you loading the file? According to this issue, the problem arises if you load it as an ECMAScript module which do not contain __dirname.

https://github.com/nodejs/help/issues/2907#issuecomment-671782092

Following the documentation below you may be able to resolve the issue: https://nodejs.org/api/esm.html#esm_no_require_exports_module_exports_filename_dirname

import { fileURLToPath } from 'url';
import { dirname } from 'path';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

My code before was like below.

app.use(express.static(path.join(__dirname, 'public')));

And I got this error.

ReferenceError: __dirname is not defined in ES module scope

And I solved this by adding code below.

import path from 'path';
const __dirname = path.resolve();

There's usually no need to import from 'url' or 'path'.

E.g. (using ESM)

fs.readFileSync(new URL('myfile.txt', import.meta.url));

will read myfile.txt from the directory of the JavaScript file (not from the current working directory).