Bot trying to connect

Almost impossible to avoid bots trying to connect
you can always restrict access to management, with trusted host and so on.

Hi

To block bot attempts targeting HTTPS access to your device, you can use the Local-In Policy feature to deny unwanted traffic, restrict administrative access to trusted IPs, and consider geo-blocking if the source is from unwanted regions. Please refer to the following document.

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Use-local-in-policy-to-restrict-unauthorized-login/ta-p/297808

It is definitely not recommended to open any management access on the internet facing interface.