Hi, StoreLink.
May we all always be under the protection of God Almighty.
I’m sorry…
In the beginning, this feature (add note) when Checkout details can still be used by us at free plan.
Currently, why is that great feature disabled? We still want to feel your kindness for that.
Hope it can be reconsidered.
Thank you very much for helping the little people. 
Hi,
Are you referring to the custom checkout field in the design section?
We moved custom checkout fields to the paid plan because we felt they are a feature used by power users. We needed some features in the paid plan to continue maintaining this product in the future.
We still offer unlimited products, unlimited orders, 0% payment gateway commission, etc, in a free plan and the paid plan starts at just $10-$14/mo.