The term Active Flow Control encompasses a surprisingly wide array of techniques [1]. Most of them are far more subtle that a Harrier like vectoring of exhaust gas.
Personally I'm a fan of "Electrically powered plasma actuators" which can use a high voltage AC source to alter how well the airflow sticks to the wing, and actively reduce drag. Here's some info I read about 2 decades ago on that approach[2] There were open source experiments with high voltage AC and lamp cord wire ("zip cord") in the year 2000.[3]
The more time goes on, the more stuff I see as "leading edge" that I read about 20 years ago. ;-)
[1] https://www.aerospacetestinginternational.com/features/is-ac...