How does this look? A piece of PTFE tubing (Capricorn) in the hole of my Sovol filament dryer, held to the frame with a guide (Sovol SV06 Clip-On Bowden Guide by Brianne | Download free STL model | Printables.com) and then as I assume you have, the tubing just held to the extruder head through tension. A zip tie to the cable also helps I think.