Looks like the built in footprint “Package_TO_SOT_SMD:SOT-23-3” is missing its 3D model. I checked the GitLab and it looks like it is missing there too: Package_TO_SOT_SMD.3dshapes · master · KiCad / KiCad Libraries / KiCad Packages3D · GitLab
Am I making a mistake or is it actually missing?