The process is reasonably straight forward but by no means simple.
- At the Desktop, select the folder containing the project and right click on it then select Duplicate.
- Rename the duplicated folder to your new project name.
- Open that project in Xcode.
- Rename the Identity of the project and the Bundle Identifier then in the File Inspector, change the Name there too.
- Press the Enter key on the “Name” field and respond to the dialog box presented by selecting “Rename”
- Now you need to “Manage Schemes” to make the final change so select the project name (as indicated in the following image) then and choose the option “Manage Schemes” from the dropdown.
- Deselect the old project name (tap the box to uncheck it)
- Tap on the + sign and add the new scheme.
- Click on OK to add the new Scheme name.
Click on Close and you can now build your newly named copy of the original project.
If you wanted to, you could go back to the “Manage Schemes” editor and remove the old Scheme by selecting the row so that it is highlighted
and then tap on the minus sign “-” to remove the old scheme. You will receive an alert to confirm you want to delete the old scheme so Tap on Delete.
This video is years old but fundamentally the process she used is much the same even though that was Xcode V6.1.1 and there are some minor differences that she used compared to the method you would use in Xcode 11.6 which is the version I am using.