A 54-yeаr-оld mаn presented with prоgressive shоrtness of breаth, intermittent fever and a dry cough for 6 weeks. He is a non-smoker, with no known medical history. He noticed weight loss and chronic diarrhoea for the last 6 months. On clinical examination, his respiratory rate was 24/minute, and peripheral oxygen saturation was 90% on air. Diagnostics: • HIV-1 antibody/antigen test was reactive• Serum (1—3)-β-D-glucan was elevated (>6 pg/ml)• High-resolution CT of the chest showed widespread geographic ground-glass opacifications, with subpleural sparing What is the next most appropriate step in management?