Transfering a file from Local Machine to an EC2 instance without Key Pair

I need to transfer a file from my local machine to an EC2 instance. I don't have the key pair. I normally get into the ec2 instance via SSM Manager. Now, I need to move a file from my local machine into the EC2 instance with scp command. The scp requires key pair name to send to file to the ec2 instance, so the command fails. Is there anything else I can do to move the file without the key? Any recommendation to fix this will be highly appreciated.