Create metafield definition on app install via webhook?

Webhooks and Events
1

Trying to add a product Metafield definition when an app is installed to familiarize myself with requests and such. Is there not an APP_INSTALLED webhook? I checked documentation and could not find anything besides an APP_UNINSTALLED hook.

Will the APP_SUBSCRIPTIONS_UPDATE be sufficient? Or is there a more optimal way to do this type of thing? Below code is how I currently have it implemented, but my “/webhooks/app-installed” callbackUrl is never reached it seems.

Hooks in shopify.server:

hooks: {
    afterAuth: async ({ session }) => {
      shopify.registerWebhooks({ session });
    },
  },
webhooks: {
    APP_SUBSCRIPTIONS_UPDATE: {
      deliveryMethod: DeliveryMethod.Http,
      callbackUrl: "/webhooks/app-installed",
    },
},

app-installed.tsx:

import type { ActionFunctionArgs } from "@remix-run/node";
import { authenticate } from "../app/shopify.server";

export const action = async ({ request }: ActionFunctionArgs) => {
  try {
    const { admin } = await authenticate.webhook(request);
   
    const response = await admin?.graphql(
      `#graphql
      mutation MetafieldDefinitionCreate($definition: MetafieldDefinitionInput!) {
        metafieldDefinitionCreate(definition: $definition) {
          createdDefinition {
            id
            namespace
            key
            name
            description
            type {
              name,
              category
            }
            ownerType
          }
          userErrors {
            field
            message
            code
          }
        }
      }`,
      {
        variables: {
          definition: {
            namespace: "example_namespace",
            key: "example_key",
            name: "Example Metafield",
            description: "An example metafield definition",
            type: "single_line_text_field",
            ownerType: "PRODUCT"
          }
        },
      }
    );

const data = await response?.json();
return new Response('Metafield created successfully', { status: 200 });
  } catch (error) {
    console.error("Error in action:", error);
    return new Response(JSON.stringify(error), { status: 500 });
  }
};

export default action;
2

There is no APP_INSTALLED webhook.
APP_SUBSCRIPTIONS_UPDATE triggers only when app subscription is updated. For example, when the merchant approves charge or cancel subscription.

I think you can create the product Metafield definition in afterAuth.

    afterAuth: async ({ session }) => {
      // add product metafield definition
      shopify.registerWebhooks({ session });
    },