This approach uses the Azure CLI to push your Docker file and context to the cloud. Then build it, tag it and save to Azure Container Repository. The following command is an example of how to do this.
az acr build --registry myregistry --platform windows --image sitecore-9.3-cm-fromacr-build:v1 .
For more information see Container Registry Setup
Note: To ensure integrity of the core ‘custom website’ images, you should avoid sending local builds to the Azure Container Repository. Instead you should trigger a build via a PR to one of the main branches.