Share Transfer procedures in Private limited

Greetings

I was searching for share transfer procedures in the Companies act, 2013 and stumbled upon more procedures listed in corpbiz website and it goes:

"

To initiate the procedure of Transfer of Shares in Private Limited Company, the following steps must be followed–

1. The Articles of Association or AOA must be reviewed before initiating the Transfer of Shares, and any restrictions mentioned must be identified.
2. The Shareholders are required to submit a notice to the directors in writing. The notice must include information regarding the intention of the share transfer.
3. The share transfer price must be identified as per the Articles of Association. The shares are first offered to the company’s existing shareholders as per the given price.
4. The company’s existing shareholders are informed about the shares available for sale, the last date of purchase and the prices at which the shares are made available for sale. If any existing shareholders are interested in the purchase, the shares are sold to them. If no existing shareholders are interested in the purchase or extra shares are available, then they are made available to people outside the company."

But I couldn't find the source in Companies act, 2013. Can someone enlighten me regarding where it is stated and why we should follow these procedures?