I ran into the same issue.
Due to a small mistake in setting up the project in firebase, I had to delete it.
But later, I realized that my application NEEDS the default project to be hosted from firebase.
Since I found no shortcuts and running out of time, I did "this" to fix the issue in 10 minutes...with a 5-Step-Process. This is not a "Clever tip". But if you want things up and running soon, you can try this...
Create a new project (in my case, it's React project in VS Code IDE) using - npx create-react-app newprojectname to create a new react project with a different file name.(Don't delete or replace your previous project yet... )
While the new project is being created, create a new project in firebase to host your project.
Copy the folder from your old project that has all your work (it's "src" folder in case of React) and replace the "src" folder in the new project you created in your local machine.
Install all dependencies...Don't forget to add any dependencies you added to you old project. Look at the package.json file of the old project and import all dependencies.
Hit the start command (npm start in my case) and see your project running.
*I'll update if I found some firebase secret to resolve this issue. You can look for the same.