flectra/addons/payment_adyen/views/payment_adyen_templates.xml

<?xml version="1.0" encoding="utf-8"?>
<flectra>
    <data noupdate="1">
        <template id="adyen_form">
            <input type="hidden" name="data_set" t-att-data-action-url="tx_url" data-remove-me=""/>
            <input type="hidden" name="merchantReference" t-att-value="merchantReference"/>
            <input type="hidden" name="paymentAmount" t-att-value="paymentAmount"/>
            <input type="hidden" name="currencyCode" t-att-value="currencyCode"/>
            <input type="hidden" name="shipBeforeDate" t-att-value="shipBeforeDate"/>
            <input type="hidden" name="skinCode" t-att-value="skinCode"/>
            <input type="hidden" name="merchantAccount" t-att-value="merchantAccount"/>
            <input type="hidden" name="shopperLocale" t-att-value="shopperLocale"/>
            <input type="hidden" name="sessionValidity" t-att-value="sessionValidity"/>
            <input type="hidden" name="merchantSig" t-att-value="merchantSig"/>
            <!-- URLs -->
            <input type='hidden' name='resURL'
                t-att-value="resURL"/>
            <!-- custom -->
            <input t-if="merchantReturnData" type='hidden' name='merchantReturnData'
                t-att-value="merchantReturnData"/>
            <!-- shopperEmail is not included for SHA-1. To avoid breaking compatibility,
                    include only if filled in -->
            <input t-if="shopperEmail"
                type='hidden' name='shopperEmail' t-att-value="shopperEmail"/>
        </template>
    </data>
</flectra>