I could make my app work by changing the config.toml.
logLevel = “debug” in the [global] section was deprecated, so I had to use the following instead:
[logger]
level = “debug”
I also set the WEBSITES_PORT to 80 (matching my Dockerfile) and selected the Always on option in  general settings, as suggested in previous comments.
The pricing tier I am using for the appservice plan is B1.
Hope this helps you.
Best