When can you fill in the Visit Japan website?

Hello Everyone,

So my flight to Japan is on 11 September 2024. I already got my visa, but I read that we need to fill in information on the Japan website so we don't have to wait long for immigration. Can I do it from now? Or is there any rule that requires you to fill in a few days before the flight? When can you fill in the Visit Japan website?

Thank you.