When that happened to me I took a piece of the old white tube down to the local hardware store. They found a brass union that would fit remaining tubing on the back of the frig and clear tubing.
Take the access panel off, put the union on the remaining white tube, put some clear tubing on the other end and thread through the access panel as you're reattaching it. Mine has been like that for about 5 yrs.
If you decide to replace the entire tube, it starts right behind the drain tray in the frig. Be sure it has a chance to cool off.
Joe, Mary and Dakota, the wacko cat
Fulltiming since 2006
2006 Dodge 3500 QC CTD SRW Jacobs Exhaust brake
2017 Open Range 3X388RKS, side porch