Unable to change Environmental variables during deployment

[daemel]

I am receiving the following error below when running the Deploy TRE workflow.

I've set the following Env variable in the workflow Env settings to P1v2, with no change in the error
API_APP_SERVICE_PLAN_SKU_SIZE
APP_SERVICE_PLAN_SKU_SIZE

Error: creating Service Plan: (Serverfarm Name "plan-airlock-" / Resource Group "rg-"): web.AppServicePlansClient#CreateOrUpdate: Failure sending request: StatusCode=401 -- Original Error: Code="Unauthorized" Message="This region has quota of 0 PremiumV3 instances for your subscription. Try selecting different region or SKU." Details=[{"Message":"This region has quota of 0 PremiumV3 instances for your subscription. Try selecting different region or SKU."},{"Code":"Unauthorized"},{"ErrorEntity":{"Code":"Unauthorized","ExtendedCode":"52039","Message":"This region has quota of 0 PremiumV3 instances for your subscription. Try selecting different region or SKU.","MessageTemplate":"{0}. Try selecting different region or SKU.","Parameters":["This region has quota of 0 PremiumV3 instances for your subscription"]}}]

Issue / Need

1. In Dev environments we need to un-select App Service Plans or be able to run them on something essentially free rather than the Premium versions of App Service Plans that are constrained.

2. We need a reliable method of setting SKU sizes in the Env variables.

3. We need this documented as today we can only find variable settings by reading the code.

[tamirkamara]

Thank you for opening this (duplicate of #7).
We currently don't have an easy way to set every setting that is used by the system. This was a concise decision to simplify and have admins set the main things.
However, since higher-end AppService Plans are not as easy to come by as they use to, we'll provide this setting as well.