Not exactly true.

Antifa is the violent branch of the organization.

BLM is the group that tries to appeal to normies.

What they try to do is to have a large group of nonviolent people at each riot (sponsored by BLM). Then the violent people (Antifa) can dart in and out of the crowd as they do acts of violence.

For example, professional athletes all publicly endorse BLM. None of them endorse Antifa, or acknowledge its existence.