The three 450 Chinese dirtbikes offered in the US are from SSR Motorsports, Pitster Pro, and Christini. The SSR imports and rebrands the same Asiawing bike you ride and only offers it with a carb. Pitster Pro might import and rebrand the Kayo like you showed (we have discussed Pitster Pro offering bikes possibly OEM by Kayo) and theirs uses a carb as well. Leaving Christini. Christini offers the Asiawing bike like you have, but they use the fuel-injected 450cc engine. Better yet, they sell the bike with 2 wheel-drive! Yes, two-wheel drive!!
Also, theirs is the only 450cc Chinese dirtbike that is street-legal in all 50 US states. Here in the US, its suggested retail price is $10,000 USD, so I am sure shipping and tariffs will be quite expensive if you tried to import one directly to Pakistan. But it does look intriguing!
https://www.christini.com/bikes/christini-awd-450