Cannot stop the browser from auto launching

Avast Secure Browser Avast Secure Browser for Windows
1

I see no check-box to change the setting.

2

In your browser settings (the tree dot menu)
Look for this:

https://d1ka0itfguscri.cloudfront.net/Lh/2021/08/11/22/11/crjX3XVj0GQ/preview.jpg

Make sure it’s not turned on.