Hi @Anonymous ,
If you are the one who are trying to login and want to capture log, then yes you can using browser dev tools BUT the portal will not give you access to report to review how many customers faced "authentication error" for example. there is no entity that has this option that i am aware of , instead they offered to enable custom diagnostic in azure blob which will do just that.
not that answer you would like but unfortunately thats whats available
hope this help
