Hi @codynew
Thank you for the question.
You can make use of the acf/settings filter to restrict the number of people who can edit the ACF fields.
The code will look as follows:
add_filter('acf/settings/show_admin', 'my_acf_show_admin');
function my_acf_show_admin($show) {
// provide a list of usernames who can edit custom field definitions here
$admins = array(
'user_name_1', 'user_name_2'
);
// get the current user
$current_user = wp_get_current_user();
return (in_array($current_user->user_login, $admins));
}