Hi – I’m having the same issue. I submitted a ticket but haven’t heard back. I’ve tried to set this up multiple times, and I always receive the same error when I go to check out from the post:
Error:
Invalid Regular period. You must specify valid values for the A3, P3, and T3 parameters for a subscription.
Post:
https://www.guerrillawordfare.com/2016/06/lizzy-ford-paperback-subscriptions-are-back/
All of the fields (A3, P3, T3) are completed – with no special characters just in case they throw off the plugin – and I’ve checked the documentation provided to ensure I’m doing it correctly. So …. I’m not sure where to go from here!