In order to use multiple GPUs with Unreal Engine, you will need to enable Multi-GPU support in the engine’s settings. This can typically be done by going to the “Project Settings” menu, then selecting the “Rendering” category and enabling the “Enable Multi-GPU Support” option.
Additionally, you may also need to configure your GPU settings in the operating system to ensure that Unreal Engine is able to access both GPUs. This can typically be done through the NVIDIA or AMD control panel, depending on which type of GPUs you are using.
You can also make sure you are using the latest version of the engine which may have better support for multi-GPUs.