How to Correctly Install TensorFlow Object Detection API

First, enter: !git clone https://github.com/tensorflow/models.git
Then: !git clone https://github.com/cocodataset/cocoapi.git
Copy the pycocotools folder from cocoapi/PythonAPI to tensorflow/models/research directory.
Then, download Protobuf:
From the protoc releases page download the latest protoc-*-*.zip. release (e.g. protoc-3.12.3-win64.zip for 64-bit Windows).
Extract the contents of the downloaded protoc-*-*.zip in a directory <PATH_TO_PB> of your choice (e.g. C:\Program Files\Google Protobuf).
Open command prompt and cd to tensorflow\models\research.
Run “<PATH_TO_PB>\protoc-3.4.0-win32\bin\protoc.exe” object_detection/protos/*.proto --python_out=.
To test if this worked properly, go to the object_detection/protos folder, and make sure there are .py files.
Next, install Object Detection API:
Copy the setup.py file from tensorflow\research\object_detection\packages\tf2 to tensorflow\models\research\
Open command prompt and cd to tensorflow\models\research.
python -m pip install.
To test the installation, try python object_detection/builders/model_builder_tf2_test.py within TensorFlow/models/research/.

References

Mark Labinski's Installing TensorFlow Object Detection API
The TensorFlow 2 Object Detection API Tutorial