Delete _Session in afterDelete Cloud Code

For someone like me (mechanical engineer self-learning swift) is JS very unreadable, indeed. I’m looking through the cloud docs, but I can’t figure out why my further extension of your function does not work:

Parse.Cloud.afterDelete(Parse.User, ({object, log}) => {
  const query = new Parse.Query(Parse.Session);
  query.equalTo("user", object);
  query.find({useMasterKey: true}).then((sessions) => {
    return Parse.Object.destroyAll(sessions, {useMasterKey: true});
  }).catch((error) => {
    log.info(`Error finding related session ${error.code}: ${error.message}`);
  });

  //setting profile status to "deleted", before it gets cleaned after 30 days
  const profileQuery = new Parse.Query("PrsProfile");
  profileQuery.equalTo("objectId", object.id);
  profileQuery.first({useMasterKey: true}).then((profile) => {
    log.info(`to be marked as delete: ${profile}`);
    profile.set("stts", 3);
    return profile.save({useMasterKey: true});
  })
  .catch((error) => {
    console.error("Error while setting profile status to delete " + error.code + " : " + error.message);
  });
});

What I want to achieve is that after user deletes his account, his profile object changed a status field to different value, letting other know that was deleted. This is closest I could get, getting error that shows that it at least tries to write something:

Error while setting profile status to delete 119 : Permission denied for action addField on class PrsProfile.

there is already field “stts” in the class, so there might also be some wrong syntax. If you would spot anything wrong I would appreciate a little help!

Thank you!