outside of the:
PHP Warning: Illegal string offset 'subjectAltName' on line 33
error, are you experiencing any others?
and can you be a little bit more specific to how it does not work?
should show a green, red or orange bar within your footer with the ssl information.
As I can not yet found an alternative to correcting that error, you can actually hide the errors by turning debug display off:
define( 'WP_DEBUG_DISPLAY', false );
Once this is placed in the wp-config.php, you should be able to see the extension working accordingly like it does on https://philipjewell.com
Have just updated this error thanks to user: @akaracing