Magento 2 Fileld email template dropdown is not defined in System XML

Question

i create a system xml to load a field dropdown for selecting email template, but when i access the configuration page there is an error like this:

Exception #0 (UnexpectedValueException): Email template 'paymentconfirmation_general_payment_confirmation_email' is not defined.

here's my system.xml:

<group id="general" showInDefault="1" showInStore="1" showInWebsite="1" sortOrder="10" translate="label">
                <label>Payment Confirmation E-Mail</label>
                <field id="email" showInDefault="1" showInStore="1" showInWebsite="1" sortOrder="1" translate="label" type="text">
                    <label>Store E-Mail Receivers</label>
                    <comment>Insert ',' between e-mail addresses</comment>
                </field>
                <field id="payment_confirmation_email" translate="label comment" type="select" sortOrder="2" showInDefault="1" showInWebsite="1" showInStore="1">
                <label>E-Mail Template</label>
                <source_model>Magento\Config\Model\Config\Source\Email\Template</source_model>
                </field>
            </group>

here's my config.xml:

<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Store:etc/config.xsd">
    <default>
        <paymentconfirmation> 
            <general>
                <email/>
                <payment_confirmation_email/>
            </general>
        </paymentconfirmation>
    </default>
</config>

Answer 1

Create a email template config.

Vendor/Module/etc/email_templates.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Email:etc/email_templates.xsd">
    <template id="paymentconfirmation_general_payment_confirmation_email" label="Email Form" file="email_template.html" type="text" module="Vendor_Module" area="frontend"/>
</config>

Inside config.xml, change <payment_confirmation_email/> to following

<payment_confirmation_email>paymentconfirmation_general_payment_confirmation_email</payment_confirmation_email>