Works like "do_shortcode" but for Gutenberg blocks.

do_gutenberg.php

function do_gutenberg( $content ) {
    $output_rendered = "";
    $parsed_blocks   = parse_blocks( $content );
    if ( $parsed_blocks ) {
        foreach ( $parsed_blocks as $block ) {
            $output_rendered .= apply_filters( 'the_content', render_block( $block ) );
        }
    }
    return ( $output_rendered );
}