subscribers not able to upload

Hi,
I want my subscribers to be able to upload a profile picture on my memberpress site. I followed this tutorial:
https://docs.memberpress.com/article/300-how-to-add-user-profile-image-tab-to-the-account-page

It works when I’m logged in as an admin, but not as a subscriber.

I already tried to give the wp role ‘subscriber’ more capabilities like this:

if ( current_user_can('subscriber') && !current_user_can('upload_files') )
add_action('admin_init', 'allow_subscriber_uploads');
function allow_subscriber_uploads() {
$subscriber = get_role('subscriber');
$subscriber->add_cap('upload_files');
}

but this didn’t work either. What am I doing wrong?

The memberpress support does not know what the problem is either

Best