Here is the code.
# Using AWS CLI to launch a Free Tier EC2 instance
aws ec2 run-instances \
--image-id ami-0c55b159cbfafe1f0 \
--instance-type t2.micro \
--key-name MyKeyPair \
--security-group-ids sg-903004f8 \
--subnet-id subnet-6e7f829e \
--tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=MyFreeTierInstance}]'