https://techcrunch.com/2019/08/21/second-docking-adapter-for-commercial-crew-vehicles-installed-on-international-space-station/

The International Space Station is now more than ready for crew-carrying spacecraft flown by commercial companies to pay it a visit: The second planned International Dock Adapter (IDA) was installed on the Space Station during a spacewalk by NASA astronauts Nick Hague and Andrew Morgan earlier today.

The dock adapter, actually IDA-3 since the first IDA was lost during the SpaceX launch failure of its CRS-7 mission on June 28, 2015. IDA-2, which was intended to be the second installed on ISS, instead became the first and was delivered in July 2016 during the SpaceX CRS-9 resupply mission.