'BadRequestException: A network route can only be specified for an on-prem push input.' When creating an input in mediaLive for RTMP Push

You may want to review the RTMP-Push setup procedure for MediaLive here https://docs.aws.amazon.com/medialive/latest/ug/input-create-rtmp-push.html

When creating the RTMP-Push input, what is being selected for 'Network Mode'? If the RTMP source is coming from outside of the AWS, such as an on-prem encoder, select 'Public'.

Then, what is the Security Group being selected or created? This is used as a filter to allow the RTMP input only from a specific set of IP addresses.

Note: The labels that MediaLive uses for the RTMP-Push input are Application Name and Application Instance. The device or application providing the RTMP stream may label these as Server and Stream Key or Name and Stream. Keep in mind if you are using a Standard MediaLive channel, two RTMP-Push destinations need to be entered.