The commission was directly given to the apostles but indirectly given to the ecclesia in every generation. After the early apostles died, the commission remained – and so does the authority, until it is fulfilled it will remain in force.
So they had a commission and were sent to fulfil it. In their generation the church grew like crazy and changed everything, everywhere. We have the same commission and we are sent to do it. That’s the key, they went, because they were sent. That’s an apostolic church.