Creating project groups
Before creating a new project group, you need to prepare a JSON request body that includes the ID of the project type, client, and locales that you want to use, as well as the internalName of each asset that you want to be translated as part of the project group.
Before you begin
Make sure that you have the appropriate permissions to create project groups. Otherwise, WorldServer will return a 403 Forbidden status code.

Also, you need to use already uploaded assets or to upload new assets. If you want to use already uploaded assets, you need the internalName of each file. If you want to use new assets, upload them into WorldServer.
After you upload an asset through the API, the response includes an

internalName property. Take a screen shot of it or write down its value. You will need it in all operations involving uploaded assets.