This trial is testing a new antifungal drug called olorofim against an existing treatment, AmBisome®, in patients with tough fungal infections. These patients have limited options because their infections resist current treatments or they can't tolerate them. Olorofim works differently from other drugs, can be taken orally, and has fewer interactions with other medications. AmBisome is a liposomal formulation of amphotericin B, known for its broad-spectrum antifungal activity and reduced toxicity compared to conventional amphotericin B.