WHMCS email help. Trying to add custom field but its not working

I hope someone can help. i posted this in the whmcs forums but i think ill get a quicker reply in here.

I added 2 custom client fields in whmcs and i am trying to add them to a custom email and its not working.

My custom field is Amazon Username it is a text box

I have put in my email ... Username: {$client_custom_field_amazonusername}

When i send the email its not showing up the amazon username as it should, its just displaying Username: {$client_custom_field_amazonusername}

What have i done wrong?

 

what version of whmcs are you using?
do you still need help?

sorry for delay just saw it now