Even though it is for an eSIM application, we ask for your preferred physical pickup location if you sign up with your passport as identification document (any IDs that does not have your current Japanese address); the whole process cannot be entirely online.
Since there are stringent laws on Voice + Data SIM use in Japan due to past fraud and misuse cases, it is mandatory for providers to do a face-to-face ID check under the condition above.
If you have the following as identification document, then the whole process of the eSIM application can be done entirely online:
1) Residence Card with your address registered on it;
2) Japanese Driver's License;
3) Japanese MyNumber Card.
Please read here for further details on the procedure in receiving your eSIM: