Empty subscription duration when creating a subscription manually

Hello,

A plan don't have a duration.
When you configure a product with a plan, you choose the duration of the subscription and its price.

So when you create manually a subscription in the backend, there is no product, there is no price and there is no duration.
That's why when you create a subscription manually in the backend, you have a field to select the end date.
The backend gives you the access to all values ; you can change the state, the end date, and so on.

The backend is not the right place to create subscriptions if you want to follow the process.
The real process is in the front-end, when the customer place a product in his cart and confirm it.
Now if you do want to give free subscriptions you can create HikaShop coupons so the customer will be able to validate its card (and subscription) for free (one short, without recurring).

Regards,