If you want your flow to send via a certain channel, you can set the channel(s) by using a Split by Expression action using the @channel.name expression. 

In the following example, we’re setting our flow to run over a Telegram channel:

Here’s how we set up the Split by Expression action:

Flows are not channel specific. However, by splitting on the channel name at the beginning of a flow, you can ignore the channel(s) you don’t want to use. 

Click these links to learn more about channels and setting a contact’s preferred channel.