How Do I Block Unauthorized IPs from Accessing My Screenly System?

Hi everyone,
Iam using Screenly for my digital signage, but I’ve noticed some strange attempts to log into my admin panel. How can I block certain IP addresses https://19216801.pro/ from accessing my Screenly setup? I just want to make sure my system is secure from anyone trying to mess with it. Any tips or plugins, previously if anyone faced this kind of issue let me know ,any suggestions and tips are welcome.