how to stop sharing texts from iPhone to MacBook

“Texts” refers to two entirely different types of messages.

• iMessages, sent to/from Apple devices. These are not “shared”, but independently communicated to/from your Mac.
• SMS/MMS messages, sent to/from cellular telephones. Stop sharing these at Settings > Messages > Text Message Forwarding on your iPhone.

See this link --> Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch - Apple Support