All you need to do is send the word "resist" to @resistbot on Twitter to start the process, similar to the text messaging system. You can write to your congress people, your governor, send a letter to the editor of your local paper, and even find the closest town halls, Swing Left district or Mueller rally. Resistbot can send you daily reminders to get political, as well. The service is free, and using it on Twitter (as well as Messenger or Telegram) will save on text message fees for the folks behind the bot.
"I can use your donations for delivering more letters to Congress instead and having a greater impact in Washington," the team wrote on Medium.