How to gain reaction time and pressed key information?

During my EEG experiment, participants pressed key with a numeric key pad.

I used trigger to get the time information. Can I extract the informtion of reaction time and which key were pressed from the recorded eeg file (or anyother file)?

If so, how can I extract them?

(Now I know how to get the information of reaction time and pressed key which written as excel file during experiment. What I need now is I want to get those information not during but after experiments since the first few participants data were not written properly which was before I fixed the code for data recording so I want to get those data from the existing files.)

(I'm using MATLAB 2019a + Psychtoolbox)