Error of PoE: Failed to compile: ./src/TemplateModule.js: Attempted import error: 'useSubstrateState' is not exported from './substrate-lib'.

[xiaozeplus]

When I learn from PoE and use commend 'yarn start', an error occurred just like this:
"Failed to compile:
./src/TemplateModule.js:
Attempted import error: 'useSubstrateState' is not exported from './substrate-lib'."

But there is a line—— import { useSubstrateState } from './substrate-lib' ——in TemplateModule.js.
Actually, this file is copyed from https://github.com/substrate-developer-hub/substrate-front-end-template/blob/tutorials/solutions/proof-of-existence/src/TemplateModule.js
I don't know how to solve this issue, could you please tell me what should I do?
Thank you for the first!