Email variables of a custom module not showing

Hi,

When I insert variables of a custom module in a template and send an email selecting the template and relating to one row of that custom module, variables do not get replaced .I tried with a non custom module and some of the variables do get replaced by data. So it might be related with the fact that its a custom module.

Im working with SuiteCRM Version 7.6.5

Can anyone help me?

Thanks you.