Component/UserComponent.php
protected function validateInvoiceAddressOptIn()
    {
        $return = true;
        $optin = (int) $this->getRequestParameter('oegdproptin_invoiceaddress');
        $changeExistigAddress = (int) $this->getRequestParameter('oegdproptin_changeInvAddress');

        if (\OxidEsales\Eshop\Core\Registry::getConfig()->getConfigParam('blOeGdprOptinInvoiceAddress')
            && (1 == $changeExistigAddress)
            && (1 !== $optin)
        ) {
            $return = false;
        }
        return $return;
    }
protected function validateInvoiceAddressOptIn()
    {
        $return = true;
        $optin = (int) $this->getRequestParameter('oegdproptin_invoiceaddress');
        $changeExistigAddress = (int) $this->getRequestParameter('oegdproptin_changeInvAddress');

        if (\OxidEsales\Eshop\Core\Registry::getConfig()->getConfigParam('blOeGdprOptinInvoiceAddress')
            && (1 == $changeExistigAddress)
            && (1 !== $optin)
        ) {
            $return = false;
        }
        return $return;
    }
Validate invoice address optin.
Needed if user changes invoice address.

@return bool