It is possible to do in other tools such as ProtoPie. And you can do that in Figma with some trickery:
But this is not possible to use in the real-world scenarios. For now you can do something simple: when you click the input field, it gets automatically filled with expected data. Or just pre-fill everything, it’s just a prototype in the end, it doesn’t have to work exactly like a real app. However, I encourage you to vote for the ongoing feature suggestion: Interactive text inputs in prototype mode