When a grantholder decides to exercise their equity, it is necessary to assign an administrator to approve the exercise.
1. Navigate to Settings > Administrator settings and from the action button on the far right of the administrator, select Edit signing and approval access.
2. Find the Publishing exercises section, toggle the button to Write and Save at the bottom of the page.
This allows the administrator to approve exercises, but if you also tick the checkbox Make this admin the default exercise approver, they will be assigned the task of approving exercises by default.
It is possible to give as many administrators as wanted access for approving exercises, but only set one administrator as the default person.