Hello,
Thank you for contacting Rank Math.
Your subscription is already expired.
We never had any lifetime subscription offer for Rank Math.
If you check the invoice for your purchase from Rank Math you can clearly see below the subscription that this is billed yearly.
Don’t hesitate to get in touch if you have any other questions.
This was a offer when you start selling PRO licens, if you see date on invoice. This was an exlusive offer for the first buyer of PRO license
Hello,
We do not offer any lifetime deals on any plans we offer, and we have never had any lifetime deals either.
The renewal part is mentioned on the pricing page and in the FAQs as well:

If you have purchased a subscription from somewhere else and they stated that the subscription was a lifetime deal, we would recommend that you get in touch with them about the situation to get further clarification.
I hope that helps.
Thank you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.