“I” and “J” are two end nodes of beam element. In beam connection, I is reference and J is mobile. Beam probe reports total forces and total moments, so the results don’t indicate directions.
For example, beam I-J is along x axis (normal to y-z plane). I experiences shear force in y and z directions. Shear Force at I = sqr [(shear_y)^2+)(shear_z)^2]. Similarly, Moment at I = sqr [(Moment_y)^2+)(Moment_z)^2]. Same for J