This project is licensed under the Open WebUI License, a revised BSD-3-Clause license. You receive all the same rights as the classic BSD-3 license: you can use, modify, and distribute the software, including in proprietary and commercial products, with minimal restrictions. The only additional requirement is to preserve the “Open WebUI” branding, as detailed in the LICENSE file. For full terms, see the LICENSE document.

The license seems to me to say that you can use, modify, redistribute Open-WebUI as you want, but you can’t change the branding unless your instance has <= 50 users (or a couple other conditions are met).