In this documentation, we can check how to add custom favicon in Magento.
1) Login to Magento admin panel.
2) Go to ‘System’.
3) Click the option ‘Configuration’.
4) Go to General >> Design.
5) Select the option ‘HTML Head’.
6) Click the icon ‘Choose File’ to upload your favicon image.
7) Click the button ‘Save Config’.
That is how we can add custom favicon in Magento.
If you need any further help please reach our support department.