A good simple generator when you want a simple icon with a letter or two on it. Allows for typeface selection from Google Fonts and selection of colours, as gives different sizes and a code snippet.

The website manifest file it provides is minimal though, make sure to edit it. I’d also prefer if it defaulted to ‘browser’ rather than standalone. It leaves name/short name blank.

https://favicon.io/favicon-generator/

It’d funded by ‘coffee donations’ so don’t forget to leave a tip if you use it.