Secrets error without having added the Secrets service

I am still not getting the error that you reported above for some reason.

I am able to send and receive the email when clicking the “enabled” checkbox"

sc

That corresponds with your server function:

@anvil.server.callable  
def noticeEmail(to_adr):
  anvil.email.send(from_name="Admin", 
                 to=to_adr, 
                 subject="Welcome",
                 text="Welcome to TicketingCSF!")

(Just as a small change, notice that I used text="Welcome to TicketingCSF!", rather than content="Welcome to TicketingCSF!" which you had)

Am I replicating the same actions that should produce the error?