After the initial authentication using JetBrains Account credentials, it is not required to have a permanent Internet access to use the product. It is required, however, that a product is able to connect to the JetBrains servers at least once every 30 days. If the last successful connection was within the mentioned 30 days, no interruptions should occur. In case no connection could be established for 30 days, the product will notify the user and will allow some time to connect to the Internet before asking to close the application.
If you do not have access to the Internet at all, please see How will this change affect customers in Government, Education, and others who are unable to utilize electronic delivery or web-accessed software for more information.