This module doesn't seem to be actively maintained anymore. The module page should point that out and list alternatives.
A good alternative with Drupal 10 support seems to be:
https://www.drupal.org/project/codesnippet →
and
https://www.drupal.org/project/codetag →
for inline code blocks.
Needs work
3.0
Documentation
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.
Both modules will not have versions for Drupal 10.1. I know only two alternatives:
https://www.drupal.org/project/highlight_php →
https://www.drupal.org/project/highlightjs_input_filter →
I will update the main page and add both alternatives.
As an important note: there is a new branch, 3.0.x that works with Drupal 10(composer require drupal/geshifilter:3.0.x-dev).