Researchers are looking for new ways to treat people with endometrial cancer (EC) who have previously received treatment with platinum based therapy (a type of chemotherapy) and immunotherapy. Immunotherapy is a treatment that helps the immune system fight cancer. This clinical study will compare sacituzumab tirumotecan to chemotherapy. The goal of the study is to learn if people who receive sacituzumab tirumotecan live longer overall and without the cancer getting worse compared to people who receive chemotherapy.