protobuf requires Python '>=3.7' but the running Python is 3.6.9

[rishabhdevyadav]

I am installing the flightmare via docker; Ubuntu 18; Python 3.6.9; pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6). As per instruction pip install tensorflow-gpu==1.14 ; I am getting a error protobuf requires Python '>=3.7' but the running Python is 3.6.9 . Any solution to this ? I followed the instructions from other sites to run pip3 install protobuf==3.6.1. However I cannot see the result of pip freeze | grep tensorflow.