If you are using theme_get_settings, such as: $value = trim(theme_get_setting('my_setting')); Then in your code editor you will also be seeing undefined  function 'theme_get_setting'.  This function has been deprecated for some time.   Instead, you need to use Passing the theme.manager and theme.initialization services to theme_handler constructor as optional parameters is deprecated. These parameters are also mandatory. $theme_handler = \Drupal::service('theme_handler');Get...

To create a .pem file, is quick once you have your .p12 certificate.  I won't go through the process regarding p12 file generation as there are many sites that outline these steps.  If you cannot find a site that outlines this make a comment below and I'll point in the right direction. Open the terminal and go to the path where you save the apns-cert.p12. where and follow the below command to generate the .PEM file. The command below depends on the following two elements: Name of the...