shopware6 - Shopware Add tab to existing module tutorial give error - Stack Overflow

I'm using Shopware 6 on Dockware Docker Container. I try to add new tab to the product page.I read .html The new tab called Custom is create but when I click on it a have an error in dev tools console.

An error was captured in current module: SyntaxError:  

Here is my template cod it is the same like in tuturial. I dont know what is wrong

// <plugin root>/src/Resources/app/administration/src/view/sw-product-detail-custom/sw-product-detail-custom.html.twig
<sw-card title="Custom">
    Hello world!
</sw-card>



 // <plugin root>/src/Resources/app/administration/src/view/sw-product-detail-custom/index.js
import template from './sw-product-detail-custom.html.twig';

Shopware.Component.register('sw-product-detail-custom', {
    template,

metaInfo() {
    return {
        title: 'Custom'
    };
},

});