"We collect Personal Data that you provide in the input to our Services ('Content'), including your prompts and other content you upload, such as files, images, audio and video, Sora characters, and data from connected services, depending on the features you use... We may use Content you provide us to improve our Services, for example to train the models that power ChatGPT."
OpenAI claims broad usage rights over all user-provided content including prompts, files, images, audio, video, and characters, using them by default for model training and service improvement.