Typescript Async setInterval issue?

Let's say I have an async interval call like so:

this.async.setInterval(()=>{
        console.log(player.name.get())
    },1000)

This code works as intended within the TypeScript environment.

However, the moment I add a variable to capture the timeout ID as mentioned in the documentation:

        /**
         * Sets a timer which executes a function or specified piece of code once the timer expires.
         * @param callback - A function to be compiled and executed after the timer expires.
         * @param timeout - The time, in milliseconds that the timer should wait before the specified function or code is executed.
         * If this parameter is omitted, a value of 0 is used, meaning execute "immediately", or more accurately, the next event cycle.
         * @param args - Additional arguments which are passed through to the function specified by callback.
         * @returns The timer created by the call to `setTimeout()`.
         * This value can be passed to `clearTimeout()` to cancel the timeout. It is guaranteed that a timeoutID value will never be reused
         * by a subsequent call to setTimeout() or setInterval() on the same object (a window or a worker).
         */

With this code:

id = this.async.setInterval(()=>{
        console.log(player.name.get())
    },1000)

It no longer runs the async interval function and only returns the interval ID. There doesn't seem to be a way to run an interval solely off an interval ID.

Code with side effects is supposed to run regardless. In C, `printf` in an if statement will still run. For example:

#include <stdio.h>
if(printf("Hello")<0){
// error handle
}

 (slightly similar to Let* implicit progn in Common Lisp as well)