about config fiel to give a initial extrinsic rotation

[momoistda]

Hello,
thank you very much for publishing this nice method.
I have a question:
I have an IMU with the x-axis pointing forward, the y-axis to the right, and the z-axis pointing upwards.
My LiDAR is installed in reverse, so its x-axis points forward, the y-axis to the left, and the z-axis downwards.
In other words, to transform from the LiDAR frame to the IMU frame, a 180-degree rotation around the x-axis is required.

Where can I specify the initial extrinsic rotation parameters? Because the calibration results currently show that the rotation between the two frames is less than 10 degrees.

I look forward to your response!