Why must Friar send a message to Mantua?

Friar Lawrence must send a message to Mantua to inform Romeo about Juliet's faked death plan. He wants Romeo to be aware of the situation so he can return to Verona and be with Juliet when she awakens. The message is crucial to ensure that the couple can reunite and avoid the tragic consequences of miscommunication. Without this message, Romeo may not understand Juliet's situation and could inadvertently lead to further tragedy.