Fontawesom icons not displaying

I am trying to call fontawesome icons on my test page, but these are not appearing. I have done the following steps.

1- following script is added in Customheaderplugin
script src=“https://kit.fontawesome.com/6d1bfbd572.js” crossorigin=“anonymous”></script

2- Calling the fontawesome icons on my test page by using the following code:
i class=“fa fa-car”>
i class=“fa fa-car” style=“font-size:48px;”>
i class=“fa fa-car” style=“font-size:60px;color:red;”>

but nothing appears on test page.
The same code when testing on w3school.com, it displays the icons.

In php error log file I did not noticed any considerable error:

[25-Sep-2019 12:32:45 America/New_York] PHP Warning: Declaration of AddThisPlugin::register($category, $path) should be compatible with LazyLoadPlugin::register($category, $path, $mainContextId = NULL) in /home/seisense/journal.seisense.com/plugins/generic/addThis/AddThisPlugin.inc.php on line 168

[25-Sep-2019 12:32:45 America/New_York] PHP Warning: Declaration of CustomBlockPlugin::getBlockContext() should be compatible with BlockPlugin::getBlockContext($contextId = NULL) in /home/seisense/journal.seisense.com/plugins/generic/customBlockManager/CustomBlockPlugin.inc.php on line 134

[25-Sep-2019 12:32:45 America/New_York] PHP Warning: Declaration of DRIVERDAO::setOAI(&$oai) should be compatible with PKPOAIDAO::setOAI($oai) in /home/seisense/journal.seisense.com/plugins/generic/driver/DRIVERDAO.inc.php on line 19

[25-Sep-2019 12:32:45 America/New_York] PHP Warning: Declaration of RegistrationHandler::validate($request) should be compatible with PKPHandler::validate($requiredContexts = NULL, $request = NULL) in /home/seisense/journal.seisense.com/lib/pkp/pages/user/RegistrationHandler.inc.php on line 19

[25-Sep-2019 12:32:45 America/New_York] PHP Warning: Declaration of RegistrationForm::validate() should be compatible with Form::validate($callHooks = true) in /home/seisense/journal.seisense.com/lib/pkp/classes/user/form/RegistrationForm.inc.php on line 21

[25-Sep-2019 12:32:46 America/New_York] PHP Deprecated: Non-static method Request::getContext() should not be called statically in /home/seisense/journal.seisense.com/plugins/generic/orcidProfile/OrcidProfilePlugin.inc.php on line 283

[25-Sep-2019 12:32:46 America/New_York] PHP Deprecated: Non-static method PKPRequest::_checkThis() should not be called statically in /home/seisense/journal.seisense.com/classes/core/Request.inc.php on line 68

[25-Sep-2019 12:32:46 America/New_York] PHP Deprecated: Non-static method Request::getContext() should not be called statically in /home/seisense/journal.seisense.com/plugins/generic/orcidProfile/OrcidProfilePlugin.inc.php on line 231

[25-Sep-2019 12:32:46 America/New_York] PHP Deprecated: Non-static method PKPRequest::_checkThis() should not be called statically in /home/seisense/journal.seisense.com/classes/core/Request.inc.php on line 68

[25-Sep-2019 12:32:46 America/New_York] PHP Deprecated: Non-static method Request::getContext() should not be called statically in /home/seisense/journal.seisense.com/plugins/generic/orcidProfile/OrcidProfilePlugin.inc.php on line 231

One important thing to mention here:
I have already called the fontawsome icons by making changes in template files. These you can see in the header. But when I want to call these icons on the test page, it does not display.
I want to show these fontawesom icons on the editor page along with every editor name (orcid, google…).

Application version: latest ojs 3.1.2.1
Thanks