First, you have to enable the Enrollment Attributes in Advanced settings. Then the priority level will be set in the Enrollment Rules section. The steps are listed below.
Navigate to the Admin Menu and select Enrollment Rules.
Click the plus (+) button to create a new rule or choose an existing rule to edit.
In the rule settings, assign resources
Within the same rule configuration, locate the Enrollment Attributes section.
Here, you'll find the option to set the Priority level.
Select the desired priority (e.g., Mandatory, Required, Recommended, or Optional).