Login attempt or request with invalid authentication notification

I’m getting notifications in my HA almost every day and more than once.

Login attempt or request with invalid authentication from ec2-3-238-137-11.compute-1.amazonaws.com (3.238.137.11). See the log for details.

I’m worried if someone is trying to hack into my system.?
Can I block or prevent this ?

I’m using duckdns and SSL. What else can I do ?