A 58-year-old woman with hypertension and type 2 diabetes is found to have an estimated glomerular filtration rate (eGFR) of 48 mL/min/1.73 m² and a urine albumin:creatinine ratio (ACR) of 15 mg/mmol on two occasions. Blood pressure averages 145/88 mmHg. According to Australian chronic kidney disease guidance, which is the most appropriate next step in management?