SNS subscription stays in pending state

Can you help with this one.

I am using SES,however the subscription for bounce/compalint management stays in pending state.

I was reading the mautic docs. it says.

“Therefore make sure your Mautic installation is allowed to connect to the internet, otherwise
the subscription will remain in the pending state and won’t work”

Please advise on how do i check i mautic installation is allowed to connect to the internet.