I have made an extension package in a sandbox development environment. From from the SAndbox environment I can deploy the changes:
1) via vS code (Ctrl + f5)
2) or Publish the APP using Docker session powershell.
But in a PROD environment in a SaaS D365BC environment, neither of the 2 options above are available.
In the post -->https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/devenv-deploy-tenant-customization
It mentions that in "Extension Management", there is a "upload extension" action. But I could not see this.