in Drupal 9 Patch - Call to undefined function Drupal\visitors\

I had to download and install the module manually since it has no proper versioning for D9. I added the version for D9 to .info file/s and installed. Then had the below errors whenever I access any of the links on my local test site page at https://drupal9.test/visitors

The following are examples of the errors:

Error: Call to undefined function Drupal\visitors\Form\drupal_get_user_timezone() in Drupal\visitors\Form\DateFilter->buildForm() (line 65 of modules\contrib\visitors\src\Form\DateFilter.php)

Error: Call to undefined function drupal_get_user_timezone() in visitors_timezone_diff() (line 71 of modules\contrib\visitors\visitors.module)

Error: Call to undefined function Drupal\visitors\Controller\Report\drupal_get_user_timezone() in Drupal\visitors\Controller\Report\RecentHits->_getData() (line 161 of modules\contrib\visitors\src\Controller\Report\RecentHits.php).

I did some research and fixed all the errors and tested and all look well with no issues.

I created a patch for all diffs but still not sure if I am attaching it the proper way.

Please edit as needed as this is my first such contribution .