As others have mentioned, Ollama uses Llama.CPP under the hood and they recently released Vulkan support which is supposed to work with AMD GPUs. I was able to use llama.cpu compiled with Vulkan support with my app [1] and make it run on an AMD laptop but I was unable to make it work with Ollama as it makes some assumptions about how it goes about searching for available GPUs on a machine.
[1]: https://msty.app