Ideally, you could ask in your session. That being said O have never done so. With T during a really difficult and painful appointnent she offered for me to contact if I needed to in between sessions. Email worked best for me and worked fine with her. She didn't do text with anybody including family.

Early on with Emdr T, also early on, I was having a really hard time after an appointment with her and T encouraged me to contact her. So I emailed Emdr T and said something like I didnt know what her preferred form of communication between appointments where but I was really struggling. She emailed me back a couple of days later telling me that she doesnt check emails on a regular basis and also didn't like that email was not very secure. She asked if she could call me. She doesnt mind emails for me to make contact but if I need support she will call me back. She does text appointments reminders.