You can renew your hosting plan at any time while it's active. You have two alternative ways to reach the renewal options:
From the Billing Section
In hPanel, go to Billing → Subscriptions and click on Renew now next to the service in question:
And proceed with the payment.
From the Websites Section
In hPanel, go to the Websites section. Click on Manage next to the website in question, and search for Renew in the left sidebar:
And proceed with the payment.
If your hosting plan expired and is canceled, follow this guide: How to Restore an Expired Hosting Plan.
How to Check the Renewal Price
To see the renewal price of your hosting plan, go to Billing → Subscriptions and look for the column Renewal price:
NOTES
You can renew your hosting and other services automatically if you enable auto-renewal.
You can also change the billing cycle for your hosting plan.