Hi,
The following is stated about the default team velocity used for calculating Team capacity within Jira Plans:
If you’re using story points to estimate issues, you can only use Scrum teams in your plan. The default team velocity is set to 30 story points, and the default iteration length is set to 2 weeks.
However, it is not stated how to configure the number of story points. With that in mind, I'd like to ask if the community knows how to increase number of story points (and iteration length, if possible)?
Look forward to hear from you 
/Mike