How to add custom fonts in react native 60+

Create a file in your react native project called react-native.config.js:
In it, paste

module.exports = {
    project: {
      ios: {},
      android: {},
    },
    assets: ['./src/assets/fonts/'],
  };

assets: ['./src/assets/fonts/'], should be the path to wherever you stored your custom fonts in your project folder.
When you run the link command, it should work then.

It is very important to use with the full name of the file without extension

https://github.com/facebook/react-native/issues/25852#issuecomment-567279869