Hello. Thank you for contacting the Toolset support.
Do you want to validate the checkboxes selection to only one checkbox option using Toolset form or you want to validate it on backend admin while you add/edit the product in admin?
Hi Minesh,
Many thnks for your answer.
I want the choice benne made and validated on backend admin while I Add/Edit the product in admin. Only one choice possible.
Regards
Jean
To make taxonomies required in admin you will have to add custom plugin like or you are welcome to search for other plugin that validates the taxonomy in backend.
=> https://wordpress.org/plugins/required-taxonomies/