Automatically assign a conversation to sender

I have admin(sender) and customer role, the admin can send message to customer from my app-web, my backend service is using the https://api.intercom.io/messages api to create a conversation, After creating a message/conversation, I want the message to be assigned to the admin only if the customer reply, since the admin who initiate the conversation. I tried adding create_conversation_without_contact_reply property, however It doesn’t work because it assign unnecessary conversations to admin(sender) since the customer may not reply. Could I create a workflow related with “When a customer sends their first message” trigger? or how could I solve this issue?