The Mevo app will default to whichever Facebook account is logged into your iOS device's Safari browser.
If you wish to stream while logged into a different account (e.g. a colleague who is the admin of your business' Facebook page), launch the Safari app and navigate to facebook.com.
Navigate to the hamburger menu in the upper right corner.
Scroll down and tap 'Log Out.'
Close Safari and launch the Mevo app.
Once you are connected, tap the red button, followed by the Facebook Live logo. You will then be prompted to log into a Facebook account.