Can't Add Liscense

I just purchased a licence for the fileupload extension. When I go to forms -> plugin settings -> licenses, I can’t seem to add any. Is there somewhere else I need to add this?

I’ve also tried adding it to activation php with:

‘license_key’ => ‘key’,
‘license_status’ => ‘active’,

http://ww.wp.xz.cn/extend/plugins/ninja-forms/