Problem with tempupdate table

So i can see that there is a tempupdate table that has this structure:
CREATE TABLE `${prefix}tempupdate` (
  `id` int(12),
  `refType` varchar(100) DEFAULT NULL,
  `refId` int(12)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8mb4 COLLATE utf8mb4_general_ci ;

I can see that it does not have a primary key.

Is there any reason for that ?
Im asking this because it causes problems if i want to use it in a mysql cluster for example, where it is required for all tables to have pk.

Could it have a primary key ? 

This is a big problem. Because of this it cant be used in a mysql cluster. For that it is required for any table to have primary keys.

This is from the docs:  MySQL :: MySQL 9.0 Reference Manual :: 20.3.1 Group Replication Requirements

Primary Keys.  Every table that is to be replicated by the group must have a defined primary key, or primary key equivalent where the equivalent is a non-null unique key. Such keys are required as a unique identifier for every row within a table, enabling the system to determine which transactions conflict by identifying exactly which rows each transaction has modified.

I think will add that composite pk, i think its better then to mess with the group replication.
Thanks