To achieve this task, open central administration. Refer to the screenshot given below to know how to open the Central Administration site.
There is another way to open Central Administration directly through the URL i.e. htttp://yoururl:8888, which is the standard port number for the SharePoint central administration site.
This is the landing page for Central Administration. On the left side, in quick launch, you can have multiple options such as Application management, System settings, etc.
Here, we need to look to Manage Service Applications options under Application Management
The Service Application page is given below, where you can see the list of all the services running in SharePoint.
From the list, look for Project Server Service Application option, which contains Project Web app instances, which consists of staging and production, which you want to access to perform the restore action.
Refer to the screenshot given below to identify Project Server Service Application option.
As you click on Project Server Service Application, page redirects to PWA Instances, as shown below.
In the screenshot shown above, I have five instances. Now, it's our choice to select the instance in which we are going to perform the restore action.
Select the instance and subsequently, select Manage option from dropdown list.
Our motive is to restore the projects. Thus, select Administrative Restore Option and refer to the screenshot given below.
From the screenshot given above, you can see the list of items, if you want to restore any custom fields then select Enterprise custom fields. Similarly, if you want to restore Project, select projects.
A list of projects will display once you select Projects. Select a project and click Restore.
This is my project. I selected this and clicked on restore.
I hope my blog will be helpful for you. Thanks for reading.