I exported my survey data from the old administration account（headquarter account),which was destroied, now the survey data is in the PostgreSQL database. And then I created a new headquarter account which login in this website：
I don’t think you could create a new HQ account at the demo.mysurvey.solutions server. That would require admin permissions on that server, which you don’t have.
The demo server is publicly accessible, so it is neither desirable (for the risk of exposing your confidential research data) nor possible (for the risk of overwriting other people’s data) to restore a particular private backup on that server.
Sorry that there maybe some mistakes between our communication. Actually I have got a new HQ account，and this account is able to login in in this web page: https://demo.mysurvey.solutions（even I am not sure how I got it, maybe created in the progress I don’t familiar with or just it is the original account but I emptied my survey data unintentionally). The situation now is I have a HQ account without any data. Is it possible to improt my original data from the PostgresSQL database to the “new” HQ account?