Insert Fixed Value into database after registration

[fabiotosca3261]

Hello in a project with Version CE 2.3.7 i need to add a fixed value for every new customer that will be always the same "AU" Phpmyadmin Image 

In short in table marketplace_userdata > column country_pic once a user is registered, must be always "AU" as default rule

I made some check and marketplace_userdata is generated from a premium extension so i checked in controller some possibile useful info and i found this.

I tried to add following code but seems not correct. Any possible suggestion about how can i achieve the result?

$seller->setData('country_pic', 'AU');

  /**
     * Save Seller Data
     */
    private function saveSellerData()
    {
        try {
            $shopUrl = $this->getRequest()->getParam("profileurl");
            $sellerId = $this->_getSession()->getCustomerId();
            $status = $this->getStatus();
            $status = 1; // set each customer as seller
            $autoId = 0;
            $collection = $this->_sellerCollectionFactory->create();
            $collection->addFieldToFilter('seller_id', $sellerId);
            foreach ($collection as $value) {
                $autoId = $value->getId();
                break;
            }
            

            $seller = $this->_sellerFactory->create()->load($autoId);
            $seller->setData('is_seller', $status);
            $seller->setData('shop_url', $shopUrl);
            $seller->setData('seller_id', $sellerId);
            $seller->setCreatedAt($this->_date->gmtDate());
            $seller->setUpdatedAt($this->_date->gmtDate());
            $seller->setAdminNotification(1);
            $seller->save();
        } catch (\Exception $e) {
            $this->_helper->logDataInLogger(
                "controller_account_becomesellerPost saveSellerData : ".$e->getMessage()
            );
            $this->messageManager->addError($e->getMessage());
        }

        try {
            if ($status) {
                /* clear cache */
                $this->_helper->clearCache();
                $this->messageManager->addSuccess(
                    __('Congratulations! Your seller account is created.')
                );
            } else {
                $customer = $this->_helper->getCustomer();
                $adminStoremail = $this->_helper->getAdminEmailId();
                $adminEmail = $adminStoremail ? $adminStoremail : $this->_helper->getDefaultTransEmailId();
                $adminUsername = $this->_helper->getAdminName();
                $senderInfo = [
                    'name' => $customer->getFirstName().' '.$customer->getLastName(),
                    'email' => $customer->getEmail(),
                ];
                $receiverInfo = [
                    'name' => $adminUsername,
                    'email' => $adminEmail,
                ];

                $emailTemplateVariables['myvar1'] = $customer->getFirstname().' '.
                $customer->getMiddlename().' '.$customer->getLastname();
                $emailTemplateVariables['myvar2'] = $this->backendUrl->getUrl(
                    'customer/index/edit',
                    ['id' => $customer->getId()]
                );
                $emailTemplateVariables['myvar3'] = $this->_helper->getAdminName();
                $this->mpEmailHelper->sendNewSellerRequest(
                    $emailTemplateVariables,
                    $senderInfo,
                    $receiverInfo
                );
                $this->messageManager->addSuccess(
                    __('Your request to become seller is successfully raised.')
                );
            }
        } catch (\Exception $e) {
            $this->_helper->logDataInLogger(
                "controller_account_becomesellerPost saveSellerData : ".$e->getMessage()
            );
            $this->messageManager->addError($e->getMessage());
        }
    }

Thanks

[LitCommerce Expert]

You can add default value for this column in InstallSchema.php

public function install(SchemaSetupInterface $setup, ModuleContextInterface $context)
{
$installer = $setup;
$installer->startSetup();
try {
$table = $installer->getConnection()->newTable(
$installer->getTable('marketplace_userdata')
)
->addColumn(
'country_pic',
Table::TYPE_TEXT,
null,
['nullable' => false, 'unsigned' => true, 'default' => 'AU']
)
;
$installer->getConnection()->createTable($table);
} catch (\Zend_Db_Exception $e) {
}

$installer->endSetup();
}

[fabiotosca3261]

Ok thanks. What is the path of installschema.php?