joel_extend_api.php

<?php

add_filter( 'wlmapi_the_members', function ( $members ) {

	if ( $members && isset( $members['members'] ) && isset( $members['members']['member'] ) ) {
		foreach ( $members['members']['member'] as &$member ) {

			$member['agent_ambassadors']         = get_user_meta( $member['id'], 'agent_ambassadors', true );
			$member['lender_ambassadors']        = get_user_meta( $member['id'], 'lender_ambassadors', true );
			$member['agent_ambassador_default']  = get_user_meta( $member['id'], 'agent_ambassador_default', true );
			$member['lender_ambassador_default'] = get_user_meta( $member['id'], 'lender_ambassador_default', true );
		}
	}

	return $members;
} );