Extend kalman filter 6dof

Hi all ,
I’am looking for a source code to use ekf filter for 6dof. But unfortunately I didn’t find all I found was for 9dof with magnetometer and I don’t have it.
I’d like to prédit only pitch and roll with gyro + accel with ekf.
I found This one or This one but I don’t know how to change it for used only gyro and accel. Is anyone have already implement ekf for 6dof with only gyro and accel?

Does this help?
Getting started with IMU (6 DOF) motion sensor - Arduino Project Hub

No because fusion data is done in the captor, I'd like to find how can I add Quaternion in Kalman with math. But many thanks to you for you link :slight_smile: