It can be seen from here that the backend modification is made by modifying the config.json file.
Regarding the path of config.json, you can open it in the directory
C:\Users\xxx.deepxde and modify it.
It can be seen from here that the backend modification is made by modifying the config.json file.
Regarding the path of config.json, you can open it in the directory
C:\Users\xxx.deepxde and modify it.