Bowden Tube Connector 5pcs Teflon PTFE Tubing Connectors 3D Printer Accessories，Plastic Metal Mixed Feed Pipe for 3D Printer Bambu Lab P1P/P1S/X1/X1C/X1E,AMS Feed PTFE Feed Tube Connector

You can get generic Bowden tube connectors off of Amazon for cheap: https://a.co/d/0gamMCIE If you're in a rush and have extra Bowden tube laying around, you can route straight from the hotend to the buffer. The only reason the connector is there is to protect the buffer/hotend for instances like this, but you can bypass if you're in a pinch.