What code piece of PHP in Stack Ideas does the user creation so I can modifiy a little and map custom fields AND core fields from Stack Ideas onto actual Joomla fields so that other components can use this info - Company Name , VAT, Address for example and one I have created called 'Requires Purchase Order' - which we need for other systems.

if (!$preferences) {

			// if preference is empty, lets get from database.

			$business = $user->getBusinessData();

			$business = [

				'business_name' => $business->name,

				'tin' => $business->vat,

				'business_address' => $business->address,

				'business_city' => $business->city,

				'business_state' => $business->state,

				'business_zip' => $business->zip,

				'business_country' => $business->country

			];



			foreach ($business as $key => $value) {

				if ($value) {

					$userPreferences->set($key, $value);

				}

			}

			

			if ($business['business_country']) {

				$user->setCountry($business['business_country']);

			}

		}



		$user->setPreferences($userPreferences);



		if (!isset($preferences['business_name']) && !isset($preferences['tin'])) {

			

			$euVatApps = PPHelperApp::getAvailableApps('euvat');

			if ($euVatApps) {



				$userPref = new JRegistry($user->table->preference);

				$userCountry = $user->getCountry();



				if (!$userCountry) {

					$this->info->set('COM_PP_APP_EUVAT_PLEASE_SELECT_COUNTRY', 'error');	

				}



				// There is a possible that user has his/her preference stored already before 'Show Billing Details' settings being disabled

				if (!$userCountry) {

					return $this->redirectToView('checkout', '', 'invoice_key=' . $invoiceKey . $excludeTemplate);

				}				

			}

		}

// We need to save user params here

		$params = $this->input->get('userparams', [], 'array');



		$files = $this->input->files->get('userparams');



		if (!empty($files) && $user->getUserName() != 'Not_Registered') {

			PP::saveCustomDetailFiles($files, PP_CUSTOM_DETAILS_TYPE_USER, $user->getId());

		}



		if ($params && $user->getUserName() != 'Not_Registered') {

			$userParams = $user->getParams();



			foreach ($params as $key => $value) {

				$userParams->set($key, $value);

			}



			$user->params = $userParams->toString();

			$user->save();

		}