How to save a ToggleControl value in a meta field?

I registered a boolean meta field called _meta_restrict in a custom post type:

PHP:

JS:

I added this meta field using a ToggleControl to the PluginDocumentSettingPanel and I can toggle it on and off, but when I save changes, the _meta_restrict key is stored in the database with an empty value.

What am I doing wrong?

Thanks in advance