Where's the Webasto Diesel heater fuses on an 2015 Etrek

Hi, new to the forum, so go easy on my beginner errors ;-) We purchased a very lightly used 2015 etrek which for where we live is a great camper van. We needed to turn the Webasto Duo heater the other night for the first time and got a 10 red blink code which appears to be something we could reset with a reboot. But to do that you need to pull and reinsert 3 fuses in a particular sequence. Nowhere in anything from Etrek does it say where they installed these fuses -- not with the others. Installation manual says they should be installed on the interior but tracing the wires get me nowhere starting from either the control or the heater its or any known fuse location. Anyone familiar with this? Probably a typical installation spot but I was surprised I couldn't find any Etrek forum anywhere with useful information. As techie as these vans are seems someone would be sharing issues. Will say it drives great and the battery only boondocking is working for us -- nice not dealing with propane and internal flames in the rig. Thanks in advance