need a pluggable hybrid that can tow 3500 libs

Kia Niro has 2866 lbs.

RAV4 Prime is 2500 lbs

Kona EV is 2800 lbs

The Tesla Model Y is really the only one that can tow 3500 lbs and be plugged in. Check out this article about the Model Y and towing:This Tesla Model Y Lost How Much Range Towing A 3,000-Pound Boat? (insideevs.com)

Otherwise, a Toyota Highlander Hybrid or Sienna Hybrid are the only fuel efficient options for towing, but they can't be plugged in. Their powertrains can also take tons of abuse and keep running.

Hyundai Santa Fe PHEV can tow 2,500.

I'm not saying this a great idea, but interestingly, here is a guy who tows 3,200 lb racecar behind his Kia Niro EV.https://insideevs.com/news/406185/video-kia-niro-ev-towing/ He does loses30 to 40 percentrangedrop, but it only costs them 7 cents per mile to tow their race car.https://insideevs.com/news/406185/video-kia-niro-ev-towing/

Bear in mind that towing capacity limits in the USA are very conservative due to our litigious society. Identical vehicles in Europe are often rated for 1,000 lbs more towing capacity. To a degree how much you tow is based on your level of risk taking. Personally I'd feel comfortable towing beyond rated capacity on occasion relatively short distance in light to moderate traffic.

BMW X3 Plug-In Hybrid is capable of towing up to 4400 pounds. Stopped Hybrid production for 2022....but was offered in 2020 and 2021. Nice vehicle...but we didn't get the Tow Package so I can't offer any personal experience regarding Towing.
The BMW X5 also comes in a Plug-In Hybrid version with an even higher Towing Capacity - I believe it's almost 6000 pounds. I have one on order.