Look for a hole in the ground behind the church, hidden among a cluster of four trees.
The most direct way to get a tank into the creator is by modifying the unit's local save file to use the tank's internal asset ID. how-to-make-a-tank-in-tabs-unit-creator
Making a tank in the Unit Creator is unique because the standard in-game editor doesn't natively allow you to select the tank chassis as a "base" for a humanoid wobbler. To truly build one, you have to use a "file-swapping" technique to change a standard unit's ID to the hidden Tank base ID. 1. The Core "Tank Base" Method Look for a hole in the ground behind