Import the additionalPackages build extension and use it in your trigger.config.ts file: 
import { defineConfig } from "@trigger.dev/sdk/v3";
import { additionalPackages } from "@trigger.dev/build/extensions/core";

export default defineConfig({
  project: "<project ref>",
  // Your other config settings...
  build: {
    extensions: [additionalPackages({ packages: ["wrangler"] })],
  },
});
This allows you to include additional packages in the build that are not automatically included via imports. This is useful if you want to install a package that includes a CLI tool that you want to invoke in your tasks via exec. We will try to automatically resolve the version of the package but you can specify the version by using the @ symbol: 
import { defineConfig } from "@trigger.dev/sdk/v3";

export default defineConfig({
  project: "<project ref>",
  // Your other config settings...
  build: {
    extensions: [additionalPackages({ packages: ["wrangler@1.19.0"] })],
  },
});
This extension does not do anything in dev mode, but it will install the packages in the build directory when you run deploy. The packages will be installed in the node_modules directory in the build directory.