Follow the below path to Add Pre Admission Fee Payment Settings

Settings --> Admissions --> Branch Admission Settings --> Select the Branch --> Payable Amount for admission --> Select the Pre Admission Academic Year, Class and click on Get --> Add

Note: If Fee Assigning at the time of Admission is Set to NO and Is Allow Payment While Admission is set to YES while admission collect the payments under the Advance fees and make sure that Minimum paid amount settings and advance fee Types are available.