good/core/views/core_templates.xml

<?xml version="1.0"?>
<odoo>
	<data>
        <template id="web_login"  inherit_id="web.login" name="web_login" >
             <!-- 登录界面email改成用户 -->
            <xpath expr="//input[@name='login']" position="attributes">
                <attribute name="placeholder">User</attribute>
            </xpath>
            <xpath expr="//label[@for='login']" position="replace">
                <label for="login" class="form-label d-flex justify-content-between">User</label>
            </xpath>
        </template>
    </data>
</odoo>