Indian citizen with <6 months US green card, 4 day vacation to Dubai - How early and how to apply for Dubai visa?

Hi,

I am an Indian citizen living in the USA with a US green card validity of <6 months by the time I travel, making me ineligible for "visa-on-arrival" in Dubai.

My trip is in December 2025. I can book hotels and flight tickets now. But how early and how do I apply for a Dubai visa?

Thanks.