The easies way is to run on this Google Colab notebook for free with GPU enabled.
It is suggested to run on a Linux machine since it could be quite challenging to install the dependencies cairocffi, or if you only have a Windows machine, running on its Windows Subsystem for Linux (WSL) is also a good choice.
Require Python 3.5+ and Jupyter notebook installed
git clone https://github.com/Tony607/keras-image-ocr
pip3 install -r requirements.txt
In the project start a command line run
jupyter notebook
In the opened browser window open
image-ocr.ipynb