Here are the steps to stop your built-in browser password manager from asking to save your passwords.
- Click the Chrome menu in the toolbar and choose Settings. 
- Under Autofill, click Passwords. 
- Turn off Offer to save passwords.  
- Click the Firefox menu in the toolbar and choose Options (Preferences in macOS). 
- Click Privacy & Security. 
- Turn off Ask to save logins and passwords for websites.  
- Click the Edge menu in the toolbar and choose Settings. 
- Click Passwords and autofill. 
- Turn off Save passwords.  
- Click the Safari menu and choose Preferences. 
- Click the AutoFill icon. 
- Turn off all the AutoFill web forms settings: Using info from my contacts, User names and passwords, Credit cards, and Other forms.  
- Click the Settings menu and choose Internet options. 
- Click the Content tab. 
- In the AutoComplete section, click Settings. 
- Turn off Forms and Searches and User names and passwords on forms, then click OK. 