Unable to create on-demand SFTP using quickstart template quickstarts/microsoft.containerinstance/aci-sftp-files

SFTP on demand (quickstarts/microsoft.containerinstance/aci-sftp-files)
Link: https://github.com/Azure/azure-quickstart-templates/tree/master/quickstarts/microsoft.containerinstance/aci-sftp-files

Details:
I'm trying to create the SFTP on-demand on Azure using the quick-start template provided however it fails to create the resources with following error:
**The image 'atmoz/sftp:latest' in container group 'sftp-group' is not accessible. Please check the image and registry credential.**

### Repro steps
1. Select custom deployment
2. Under quickstart, select the template
3. Provide necessary information such as resource group, fileshare and credentials to be used
4. Deploy. The deployment failed on the step



Some additional information might relevant:
Azure subscription type: Pay-as-you-go
User role : Global administrator

Any pointer will be appreciated.
Thanks.

Start with quickstarts/microsoft.containerinstance/aci-sftp-files and inspect how the SFTP container image is referenced and deployed. Reproduce the custom deployment using the documented inputs, then verify whether the referenced image and registry settings are accessible to Azure Container Instances. Done means the template deploys successfully and creates the SFTP resources.

Written by the indexing model from the issue text.