It seems like it is funded by creator for now. It seems like they intend to fund it via professional acesa to its infrastructure.

Here is the bit that talks about it

https://xonaly.com/ethical-private-search-engine/

> How is Xonaly sustained? > Xonaly remains free and private for users by offering professional access to its infrastructure through the Xonaly API. This allows developers and organizations to build applications on top of a truly independent search engine, while supporting the long-term growth of the project.