Why does the request path to the axios API change?

Question

Software Deployment

When publishing a client application to git-pages (React + typescript+axios), when requesting an API hosted on HEROKU (Nest). When making a request, a request is sent to the server, consisting of

https://XXXX.github.io/YYYY.herokuapp.com/achieves/?month=4&year=2021

Where the first part is inserted hostname git-pages.
i.e. it should be like this

https://YYYY.herokuapp.com/achieves/?month=4&year=2021

When developing locally, everything is ok. Compiled and uploaded. Added to the request is XXXX.github.io/