The reason why the apply fails after adding a new provider to the configuration and immediately running terraform apply in the CD using the local backend is because Terraform needs to install the necessary plugins first. Terraform providers are plugins that Terraform uses to interact with various cloud services and other APIs. Each provider has a source address that determines where to download it from. When Terraform encounters a new provider in the configuration, it needs to run terraform init first to install the provider plugins in a local directory. Without the plugins, Terraform cannot communicate with the provider and perform the desired actions. Reference = [Provider Requirements], [Provider Installation]