How much Melatoning Cream should I apply?

I'm using this.

On areas with freckles or pigmentation

I'm applying just a little bit. I haven't been using it consistently for a while.

It's been about a month...

I used a small amount of Melatoning Cream, so I couldn't see the effect

I was wondering if you weren't seeing it.

Does anyone happen to know if using a small amount is correct, or what amount is best to use?

Since I bought it at a pharmacy, I was worried that applying too much might be bad, so I didn't apply a generous amount.

I can't even remember the contents of the instruction manual.

How much should I apply?

Also, since it doesn't cause any irritation, I've been applying it consistently, but I'm wondering if that's okay too.