Rocket Lab has been developing their medium lift Neutron rocket for some time, which has planned 8500 kg, 13000 kg, and 15000 kg lift capacities (varying based on reusability) and is a step up in size from their existing Electron platform. Their launch complex made for this rocket, LC-3, is now complete. They've announced a few early customers so far, including a commercial satellite constellation, and a military cargo delivery test by the USAF.

Also "paid" in the title means not a test flight, but rather something that one or several customers have financed, i.e. part of Rocket Lab's revenue generating operations.