How do I create an activation link to be sent to customer to activate their subscriptions?

How do I create an activation link to be sent to customer to activate their subscriptions?

Hi Zoho Support Team,

I have been given a requirement to setup user subscription flow as below:
1. User send a subscription request by phone / email
2. An admin will create customer, and subscription from the zoho subscription dashboard
3. The subscription will not be automatically activated, it will need user action to activate
4. An activation link sent to customer's email
5. Customer click on the link sent to their email, and the subscription started

Would you point me the direction to get this flow working? or any workaround

Thank you very much