Quake BSP Loading

How can i load a BSP like this?

Some of the older builds of Ultra included a Quake file format plugin, which should work. You can revert to an older version, get the DLL from the plugins folder, and copy it into the latest version.

You can also use the source code here to read Quake BSP files and construct a model:
https://github.com/UltraEngine/PluginSDK/tree/master/Plugins/Quake Loader

I installed the plugin, but I'm not sure which functions to call and create a model from BSP. Do you have an article for this?

Just call LoadPlugin("Plugins/QuakeLoader.dll"), make sure you keep it in memory, and call LoadModel() to load a quake bsp file as a model.

Here is an example that uses another plugin to load PNG images in a glTF file:
https://www.ultraengine.com/learn/LoadPlugin?lang=cpp

Sorry.. my mistake. I should have tried another bsp. It worked now, thanks.