This function contains a HTML table with a form where you will add your inputs for the credentials and settings that you need from the admin.
There are two required fields: Enable and Button Caption.
‘wpjobster_’ . $this->unique_slug . ‘_enable’ // used for enabling or disabling the inclusion of your plugin in the theme.
‘wpjobster_’ . $this->unique_slug . ‘_button_caption’ // the text showing on the button which takes the user to the gateway