You can send me a secure message on Keybase. Unfortunately I cannot share information for you to contact me via iMessage or Signal, as much as I’d like to. Both of those services require a phone number (or in the case of iMessage, an email address) to communicate, and don’t allow using simply a username.
You can send me an email using this form below. (I realize web forms for email are weird, but I also don’t want to just publicly post an email address either).
If you would like to contact me securely, you can find my PGP key here.