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That is good, please ensure that you have Safari checked in your iCloud preferences on both the iPhone and iMac. If you need assistance with this please refer to iCloud - Learn how to set up iCloud

If you are using iCloud to sync Safari then this is already being done. Please verify both devices have iCloud on and are setup. Otherwise I don't know another method.

So a question to you is, do you have iCloud turned on for both devices?