@A G Thank you for reaching out to Microsoft Q&A, apologize for any inconvenience caused on this. I have understood that while creating the function app from the portal the storage section is missing. Could you please help us with more information to understand more and assist you further.
- Without the Storage section in portal where you able to review and create the function app?
- Have tried the same operation by logging-in to portal from different browser or signing out and signing-in in same browser or by clearing the browser cache.
If you still face the issue, I would request you to help us with f12 traces of the browser or the session id for the blade from the portal using keys ( Ctrl+Alt+D -> bottom right corner yellow box). As a workaround you can create the function app using the Azure CLI or through PowerShell cmdlets refer to this documentation
Feel free to reach back to me if you have any further questions on this.