how to change the URI

I have install wordpress on my webspace.
the address is: https://www.garbage.cn/ark

I have make a mistake operation.

on the wp-admin==>option
I change the wordpress URI and blog URI as https://www.garbage.cn

now, I can’t visit my blog as https://www.garbage.cn
https://www.garbage.cn/ark can’t showing complete.

How can I do let the blog can visit as: https://www.garbage.cn/ark

Pls help