@LOGANISHANTH E Thank you for reaching out to Microsoft Q&A, apologize for any inconvenience caused on this.
You can use the below cmdlet to create the function app with the custom image that is stored in the container registry as mentioned here.
az functionapp create --name <APP_NAME> --storage-account <STORAGE_NAME> --resource-group AzureFunctionsContainers-rg --plan myPremiumPlan --deployment-container-image-name <DOCKER_ID>/azurefunctionsimage:v1.0.0
Pass the Azure container registry url to the --deployment-container-image-name
For more information, you can refer to this documentation on how to create a function app on Linux using a custom container.
Feel free to reach back to me if you have any further questions on this.