Method of adding domestic sources:
Click Settings in the File menu to enter the Settings interface, and then click the+sign on the right to install Django or other packages.
Click this plus sign, and then click Manage Sources.
Then click the plus sign on the right to add the domestic mirror source. I added two, one is watercress and the other is Alibaba Cloud.
There are also some commonly used sources, which I post here for reference only.
/Simple/# Tsinghua University
/simple/ # China University of Science and Technology
/# Huazhong University of Science and Technology