I am building a slack application.
I added "incoming-webhook" to oauth scopes that let me choose the channel I want the App to post messages. However unless I ping the app in the channel to add it. I get a "channel not found" error.
Is it possible to add the app to a channel when installing app via oauth ? Without adding it manually by @app-name or /invite app-name ?
When you add an incoming-webhookscope to your app, the option to add a channel during authentication is specific to incoming webhooks not bot messages. So any messages you send via the incoming webhook will send to the channel you selected during authentication. Messages sent via [chat.postMessage][1] will require your bot to be a member of the destination channel, via invite. Incoming webhooks can only be linked to a single channel. You will have to create a new webhook for every channel you want to post to using webhooks. For that reason, I'd recommend using chat.postMessage instead. If you request the chat:write.public scope your bot will be able to post into any public channel without invitation.
