I am only sure about the the one I have on my bike . I was told early on there is a 500 that will fit as well. It is inserted from the side unlike the "integrated" one on other Giants including the 2021 on the US site. See https://www.giant-bicycles.com/us/bikes-explore-eplus
The Giant batteries that are integrated in the frame are named EnergyPak Smart. These are 400, 500, and 625 Wh.
For instance, I swap the EnergyPak Smart 500 with 625 on my Trance E+. Since you would need to order the larger battery through the authorised LBS anyway, you might ask the LBS about the compatibility to make sure.