how to create contract renewal template for procurement contracts with no lines

Summary:

Procurement Contract Manual Renewal is the template required. also what is the period that is there in the renew

Content (required):

I am trying to use the manual renewal functionality for my procurement contracts with no lines. I am trying to create a renewal template but on that there is this field call Period which is an LOV. can you please let me know how can I have the value populated and at least have the contract renewal working for procurement contracts without lines

if the renewal template is not required what are the values should be for modifier , duration and period.