Electron laser wakefield acceleration using high-intensity lasers is one of the powerful tools to achieve time-resolved pump-probe experiment with quasi-table top configurations. The high-energy electrons (and sometimes high charge) are mentioned/employed across several experimental proposals of different research activity groups at ELI-NP. In the framework of the MoU and existing collaboration for the drafting and implementation of the RA5 TDR, we have been invited to join the experiment of electron acceleration at the J-KAREN PW laser facility at Kansai Photon Science Institute, QST, Japan. The main purpose of this experiment was to accelerate and measure high energy electrons in sub-GeV range or high-charge electron bunches using Helium based gas targets – either a 10 mm gas-jet or a 20 mm gas-cell. The purpose of the seminar is to present the aspects that the ELI-NP team participating to the experiment at KPSI considers the most relevant for our implementation work and preparation for the commissioning experiments.