More details about this task.

If we browse the directory in the context of an origin (https://archive.softwareheritage.org/browse/origin/https://hal.archives-ouvertes.fr/hal-02309043/directory/),
we can see that in the permalinks tab, there is an "Add origin info" checkbox enabling to add origin information as persistent identifier metadata.

But if we browse the directory through its identifier and the origin info is provided as query parameter (https://archive.softwareheritage.org/browse/directory/ec4ae097465d9ea51589537ea94b2ea50e8d134d/?origin=https://hal.archives-ouvertes.fr/hal-02309043), the "Add origin info" checkbox is missing.

So the checkbox should also be visible in that latter case.

Thanks @anlambert for the detailed explanation.
This is exactly right !