Numbered headings and table of contents in Google Colab

Check this answer for a workaround by writing the numbers manually. https://stackoverflow.com/a/69541262/8691571

Use # 1. Heading

Its very simple Here are the steps :

1. Create a new section.
2. add "#" before the heading you want to write
3. the heading appears in the "Table Of contents"

link : https://colab.research.google.com/notebooks/markdown_guide.ipynb this link shd solve your doubt.