When a new membership is created in Memberpress, I want Zapier to add the tag of monthly to my new monthly subscribers, or the tag of yearly to my yearly subscribers in AWeber.
Below is what I used as a test for the yearly tag to be added.
What I have below works for only a particular test user, but when anybody else signs up, no tags get applied.
Hi
Welcome to the Community! 
It looks like you’re using the “Update Subscriber” action and it looks like you are only updating the same subscriber every time the Zap runs:
Could you please try changing that to the “Create Subscriber” action instead?
Kindly give it a try and let me know how it goes? I'll keep an eye out for your response!
Hi
If Subscribers might already exist in AWeber, then try these Zap steps:
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.
