app/code/Gta/AdminPay/etc/module.xml

<?xml version="1.0"?>
    <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/Module/etc/module.xsd">
        <module name="Gta_AdminPay" schema_version="0.0.1" setup_version="0.0.1"></module>
</config>