Make your communication very sure don't need to use vpn if you know that. Extension encrypt, decrypt data, can Generate key pair that will be stored in local storage, sign, check sign, store existing public key. Search your public key, send it to your friend in Facebook for example. And then you can send encrypted messages to each other. You can also use it to sign and verify signature of message. Don't hesitate to check the console if the error is not understandable. Please check the format of your key, it's really important.
Work on browser that support ES2022.
