You might want to try getting in direct contact with some developer and ask them if they are available, e.g. Coldtrick (https://www.coldtrick.com/) or Arck (https://www.arckinteractive.com).

I wish I can see someone who is ready to help me right now so I can have his or her WhatsApp number.
Pls help. I love Elgg but most of the plugin are outdated.

Moved this topic to the correct group

From Elgg documentation: 

Since 3.0, metadata is not owned and can in principle be updated by any user, who has access to the entity.

You can still use the hook to prevent the metadata from being written to the database, however it may propagate in ElggEntity properties.

 

Use ElggEntity::canEdit() before setting metadata, if you want to ensure that only owners/admins can update metadata.

You can create your own custom function or action and use:

elgg_call(ELGG_IGNORE_ACCESS, function()

for such case