Ulog file data from PX4 firmware v1.12.3 . How can I merge them

I’m performing code generation with Simulink with the PX4 tool chain add-on( UAV Toolbox Support Package for PX4 Autopilots Documentation - MathWorks Italia ). I have a problem. How can I receive the data from the drone(e.g. position,velocities, acceleration, Euler Angles and its derivatives etc… )
I’m using the file ulog that PX4 creates when I lauch a simulation but there’s a problem. PX4 creates a lot of ulog file, how can I merge them together ? And how can extrapolate a struct, matrix data to work on matlab? I already know about online px4 viewer or PlotJugger but they just show me the plots not the data.