That little flat part seems to be the piece that makes the connector proprietary and ensures that users won't hook up a power supply that is not compatible. I would consider cutting it out of the way, allowing the above linked connectors to fit. As an electrician and electronics enthusiast, I have done something similar on multiple occasions. Just ensure you are supplying the proper voltage to avoid any damage.
That little flat part seems to be the piece that makes the connector proprietary and ensures that users won't hook up a power supply that is not compatible. I would consider cutting it out of the way, allowing the above linked connectors to fit. As an electrician and electronics enthusiast, I have done something similar on multiple occasions. Just ensure you are supplying the proper voltage to avoid any damage.
I kind of got a white cherry vibe from this years
C