Add GCLID ($gclid) property to GravityForms Zoho lead

functions.php

<?php

	add_filter( 'gform_zohocrm_lead', function( $lead, $feed, $entry, $form ) {
		$gclid_keys = [ '$gclid', 'GCLID' ];
		$custom_fields = !empty( $feed[ 'meta' ][ 'leadCustomFields' ] ) ? $feed[ 'meta' ][ 'leadCustomFields' ] : null;
		if ( $custom_fields && is_array( $custom_fields ) ) {
			foreach( $custom_fields as $custom_field ) {
				$key = rgar( $custom_field, 'key' );
				$value = rgar( $custom_field, 'value' );

				$custom_key = rgar( $custom_field, 'custom_key' );
				$custom_value = rgar( $custom_field, 'custom_value' );

				if ( $key === 'gf_custom' ) {
					if ( in_array( $custom_key, $gclid_keys ) ) {
						$lead[ '$gclid' ] = $custom_value;
					}
				} else {
					if ( in_array( $key, $gclid_keys ) ) {
						$lead[ '$gclid' ] = rgar( $entry, $value );
					}
				}
			}
		}
		return $lead;
	}, 10, 4 );