After upgrading Drupal 9 to Drupal 10.2.4 "Uncaught SyntaxError: Unexpected token '<'" in js aggregation

Reformat issue summary for readability as tag per the tag guidelines..

This needs some more information, it looks like something is injecting the HTML into the aggregate response, definitely doesn't come from Drupal core.

Is this on production? If so do you have a local version of your site to compare against?

Which contrib modules do you have enabled?

What hosting environment are you using?

Can you double check that the HTML isn't in the files written to disk - it sounds from your report like it isn't, they're usually in sites/default/files/css and sites/default/files/js.

Just now I found the root cause, indeed it is due to the contrib/custom module.
A contrib module https://www.drupal.org/project/relative_to_absolute_url → is used (this module is not available for D10, it is usded in custom by fixing deprecations for drupal 10 & PHP8.2) which converts all relative URLs to absolute. (Needed for this site).
I have installed module https://www.drupal.org/project/rel_to_abs → but it not convert relative URLs to absolute.
Can you suggest any fix or any way to convert URLs from relative to absolute.

That module doesn't even have a Drupal 9 release.

It is seeking a new maintainer, you could request maintainership and if the owner does not respond use this process:

https://www.drupal.org/docs/develop/managing-a-drupalorg-theme-module-or... →

Once you have maintainership you can update for Drupal 9 / 10

The module was working fine for Drupal 9 (with some small deprecations fixes & using it in custom), but in Drupal 10 it adds extra HTML tags. I will request for maintainership.
Meanwhile is there any module or hook/code/patch to convert all URLs to absolute?
It will be a great help if you could provide any solutions.

Moving this to the project since I couldn't see an existing bug report there.

@pratishjha for alternative modules try asking in #support in Drupal slack.