everything is okay but when my friend spawn a car, my car in his game is going only forward and he is not moving. I am hosting the server
Is BeamMP his only loaded mod and does this happen on official servers?
ignore this 
you read it wrong, he is hosting the server meaning he is not in officials 
If they can see their friend moving on an official server, it’s most likely an issue with their server setup. It’s a useful troubleshooting question.