(module
  ;; Import the `greet` function from the environment
  (import "env" "greet" (func $greet))

  (func
    ;; Call the imported `greet` function
    call $greet
  )

  ;; Automatically run the first function when the module starts
  (start 1)
)
const url = '{%wasm-url%}';
await WebAssembly.instantiateStreaming(fetch(url), {
  env: {
    greet: function () {
      console.log('Hello');
      // Expected output: "Hello"
    },
  },
});

Wat Demo: call