Adding an online application to WordPress can be a daunting task, but with a little bit of effort it can be done. The first step is to create a custom plugin that will handle the application process. There are a number of plugins available that can help with this, such as WPForms or Gravity Forms. Once the plugin is installed, the next step is to create the application form. This can be done using a WordPress plugin or a simple WordPress template.
Once the form is created, it will need to be populated with the necessary information. This can be done using the plugin or template provided, or by using a plugin that can automatically gather the information from a database. Once the form is populated, it will need to be submitted to the plugin. The plugin will then process the application and return the results to the WordPress website.