WPBulky

i need to add a meta key to each post of my wordpress site (wp-postmeta) in order to shield of access of public to posts in bulk ( I have 800 posts!)

meta_key = _members_access_role
meta_value = editor

how can I achive this with the wpbulky tool … ?

i thought I would see the meta fields (inactive in free version) but I only get calssname and varname there…)