.UK domains don't use authorization codes.
For transferring .UK domains;
You have to initiate the transfer at the Current Registrar with whom you are managing your .UK domain name. You need to provide them the IPS Tag of your New Registrar (i.e. TEMOK) which is ENOM.
Once you have placed the order for your .UK domain transfer with us, you will receive a confirmation/ verificaton email which you have to approve in order to initiate the transfer process.