Warehouse name must be uername.github.io , the user name is your GitHub user name, so that 404 will not appear
but I didn’t use my user name at first, and later found that it was the same, so I went to modify my user name to keep it consistent with the warehouse name, so the final result of this operation is still 404
solution: Delete the warehouse you just built, create another warehouse with the new user name, and repeat the steps