Have you tried Free Gifts BOGO buy x get y by Secomapp? It automatically adds free gifts to your customer cart once the customers meet the condition of your offer. It doesn’t hurt to give it a try
To set this up, I recommend using the “Spend X Get Y” offer in the BOGOS App.
With this feature, you can easily define different spending ranges and assign a specific free gift to each range.
Once a customer’s cart total meets the condition, the corresponding gift will be automatically added to the cart.