When you want the bot to run more than 15 minutes per session, use an online-bot session as explained at https://github.com/Viir/bots/blob/master/guide/how-to-run-a-bot.md#online-bot-sessions
Online bot sessions cost 2000 credits per hour. To add credits to your account, follow the instructions at https://app.botengine.org/billing/add-credits
For more about purchasing and using credits, see the guide at https://forum.botlab.org/t/purchasing-and-using-botengine-credits-frequently-asked-questions-faq/837