implement flat pT generation for pi0 and eta

Author: rashigupt

MC/config/PWGHF/ini/GeneratorHF_Non_Hfe.ini

@@ -1,4 +1,7 @@
-#### This configuration uses the Hybrid external generator to trigger π⁰/η production within the specified rapidity window
-
-[GeneratorHybrid]
-configFile = ${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGHF/hybrid/GeneratorHF_Non_Hfe.json
+#### This configuration uses the Box generator to trigger π⁰/η production within the specified rapidity window
+[GeneratorExternal]
+fileName = ${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGHF/trigger/selectbox.C
+funcName = generatePythia8Box(0.1, 50.0)
+[GeneratorPythia8]
+config= ${O2DPG_MC_CONFIG_ROOT}/MC/config/PWGHF/pythia8/generator/pythia8_NonHfe.cfg
+includePartonEvent=true