One of the two requirements in order for your license to be promoted is your minimum participation requirement or your MPR.
Your minimum participation requirement requires drivers to run a certain number of races at their current license level before being allowed to graduate to the next license.
The status of your MPR can be found in your iRacing profile, which you can find by clicking Profile to the left of the iRacing UI or click on your helmet at the top right, then on your name.
You will find the information on the Licenses page
This box will show you your MPR Obligation for all licenses, and what you need to do in order to complete the requirement.
All Rookie-level series allow you to fulfill your Rookie MPR obligations, but as you move up the ladder, it can be hard to know which series will contribute to your current license. To find out, look for the Green “MPR UP” Icon in the series description on Tile Mode, or the green up arrow in List Mode.
Keep in mind that only completing your MPR obligations will not allow you to advance your license level. You must also satisfy your Safety Rating requirements in order to advance. MPR can also be achieved by running time trials, which we will cover in a separate tutorial.
Please refer to section 3.4 'Minimum Participation Requirements (MPR)' of the Sporting Code for more information.