Some explanation found in the documentation on the Kitbash website:
The following Kits are currently not available in Cargo:
- Mini Kt: Neo City
- Otoy Special Edition Kits
The Otoy Special Edition Kits are complimentary for Octane Subscribers as part of a special promotion from Otoy. This promotion is limited to the software formats that are supported by Otoy.
And as I could see, none of my Otoy kits appears in Cargo.