How does the monthly personal license work?

Hello,

Could someone explain to me how the monthly personal license works?
If I buy it once, by adding it to the shopping cart, I assume it would work for a whole month from the date of buying.
What about after that? For the following month, do I have to order it again via the shopping cart or would it be automatically deducted from the payment details I entered at the time of the first purchase?

I wrote to the customer service 3 days ago, but not yet received a response.
Would be grateful if someone could guide me.

Thanks & Regards,
Sooraj.