This is a remix of the design created by DarkArtsLab to connect your Bambu Labs P1S, X1 printers to a 2.5" exhaust hose coming down from above the printer. The holes in the mounting flange allow you to connect it via a few short sheet metal screws into the three open holes on the back of the printer. I recommend using bolt head style screws to be able to turn in the one at the top of the printer.
Supplied with these files are the 3MF, STL, STEP files as well as the SOLIDWORKS part file that I created this in. If you have access to SOLIDWORKS you can edit the file as needed.