Controls
Inner Blocks
You can use only a single Inner Blocks control per block.
Inner Blocks control creates a nested area and lets you insert all available blocks inside it. See examples below to use this control.
Usage
PHP
<p>
<?php echo $attributes['control_name']; ?>
</p>
Handlebars
<p>
{{{control_name}}}
</p>
Please be aware to output HTML in Handlebars, you should use the triple curly bracket – open
{{{
and close }}}
Post Meta
It is not possible to use InnerBlocks as Meta fields.