It is intended to forward texts that arrive on the number as a new SMS (prefixed with the sender's number) so you can read them on your phone. In the current version the forwarded copy is queued to the same Sprwt number that received the text rather than to your Call Forward To number, so it may not reach a personal phone; incoming texts are always visible in Chat and History > Received regardless of this setting. If you rely on forwarding, test it after enabling and contact Sprwt support if copies do not arrive.