How to use different local.setttings.json files in Azure function app

I am trying to create a toggle in my Azure function app, in which you are able to switch between using different local.settings.json files. My current setup includes adding a new profile in the launchSettings.json file:

{"profiles": {"TestProject": {"commandName": "Project","commandLineArgs": "host start --port 7072 --pause-on-error"    },"TestProjectQA": {"commandName": "Project","commandLineArgs": "host start --port 7072 --pause-on-error","environmentVariables": {"ASPNETCORE_ENVIRONMENT": "QA"      }    }  }}

Selecting which project at runtime will determine which settings.json file is used. If TestProject is selected, the local.settings.json file should be executed and if TestProjectQA is selected, the quarterly.settings.json file should be executed.

However, I am unsure how to execute the quarterly.settings.json file when the TestProjectQA is selected.