Yes, you can.
If you’re afraid that if you add a user at the end of the month we will charge you the full price, don’t worry.
How to purchase more Subscription seats?
Go to Settings>Subscription.
Click on Change Subscription.
You will be given an option the number of your current seats and if you use Automation, you can change the Auto increase limit as well.
You pay for what you get - we calculate the price for a proportionate part of the month the subscription was active.
However, if you remove users during the billing cycle, we don't return the payments.