ManyRequests allow you to customize the number of requests when creating services such as maximum number of active requests at a time and maximum number of requests included per month.
How To Manage Max Number of Active Tasks
Given that you've already setup your Service, here's the simple process on how to manage the max number of active tasks
On your Dashboard, go to Services and select All Services - this will show you all the services that you have
Select your desired Service to manage by clicking on the Name of the Service, or clicking on the vertical three dots and selecting Edit
Review the Service details and Select Next
On the More Details section, you can customize the Max number of current Requests and the Max number of Requests per month
Max number of current Requests - this is how many requests you want to be worked on at the same time / how many running active requests you want at a time
Max number of Requests per month - this is how many requests you want capped every month during a subscription
Click Next
Edit the Request Form as needed
Hit Save