You can add/update tier price to the Product from the Admin Panel Manually.
Just Login with Admin Panel, From Left Sidebar by clicking on Products -> Add or Edit Product -> Price (Click on Advanced Pricing).
If you have to task to add tier price in the product programmatically in Magento using add() method from the ScopedProductTierPriceManagementInterface. Continue reading “How to add update product Tier Price programmatically Magento 2?”