RuntimeError: Could not find 'input_1' in graph's inputs

sorry what you need is print(irmod). Look for the name after main like below:

def @main(%input_tensor:0: Tensor[(1, 300, 300, 3), uint8]) -> (Tensor[(1, 100, 4), float32], Tensor[(1, 100), float32], Tensor[(1, 100), float32], Tensor[(1), float32]) {