You can directly pass the two input tensors to the model and would get the output as in a standard use case:
x1 = torch.randn(1, 3, 224, 224)
x2 = torch.rannd(1, 3, 224, 224)
out = model(x1, x2)

I’m not sure where you are currently stuck, so feel free to explain the trouble a bit more.