By default, Gmail does not support you to do this, but Gmail Conversation Reversal will help you. Email threads in a Gmail conversation thread show the oldest email first, the Gmail Conversation Reversal extension simply reverses that, showing the newest email at the top.
A small but very useful change, you don’t have to scroll to the bottom of the page to open the latest email. Gmail Conversation Reversal supports many browsers (Chrome, Firefox, Safari, Microsoft Edge), you go to here or follow the link below to install.
After the installation is complete, you do not need to set up anything. You try to open the email thread or when a new email arrives, you will see the change, the latest email will show first and the older emails will be at the bottom.
The default view with new email is at the bottom of the message thread list.
New way of viewing with new email at the top of the list.
This way of displaying helps you immediately see the newly sent email and do not have to frustratingly scroll to the bottom of the email thread to see it, both confusing and time consuming.