How to connect ESP8266-01 to push button

Hello. I have a program using the ESP8266-01 to send a notification to my phone using pushbullet and pushingbox. When i upload the code, I upload it to ESP8266 Generic. I was wondering if there is any way to attach a button to my design, that would allow the notification to be sent after the button has been pressed. Is there any way to connect my ESP 8266-01 to a pushbutton?