Serverless Gps tracking Server

Hi all! i wish a great year with health!

Currently i am looking to implement a gps server that i have created with c# to aws and i would appreciate if i had any hint from you about the following case: I have created in an on Premise windows server, a gps server with c# that accept HEX messages from gps devices. The server run on specific port that i have declared and the devices needs and IP:PORT in which they could send the messages. Also the server can send back to the device commands. I am struggling on how i could create a similar aws serverless setup . I have find aws API gateway with socket but cant setup a port there and also accept messages only in json format as i have seen. Also i looked around aws iot but works with mqtt protocol but the majority of the devices cant support it now. Is there any way to create the same setup that i have on-premise to aws with serveless setup and not to need to create ec2 windows instance and upload there my c# gps server?

My ideal setup is to create a serverless flow that the device can send messages to IP:PORT with a bi-directional communication Thank you all for your time