The purpose of this study is to determine the safety and efficacy of belzutifan in combination with pembrolizumab and lenvatinib in multiple solid tumors including hepatocellular carcinoma (HCC), colorectal cancer (CRC), pancreatic ductal adenocarcinoma (PDAC), biliary tract cancer (BTC), endometrial cancer (EC),and esophageal squamous cell carcinoma (ESCC). There is no formal hypothesis testing in this study.