Are you looking to add Modded Classes to qualify them for Psionic Training? Well here is some minor advice into editing the specific line of code required for this task!

NOTE: Since Psionic Training requires a Utility Sidearm Mod that's compatible for War of The Chosen, I am using and have made a small guide for Ginger's Utility Sidearms here!

https://steamhost.cn/steamcommunity_com/workshop/filedetails/discussion/1194081262/3356799628309410565/

STEP ONE: First go to your "Steam/Steamapps/Workshop/Content/268500" Folder, then search for the folder named "1565155767", and open it. You will then find "Config", open the file.

STEP TWO: Open the "XComUtilitySlotPsionicsWOTC.ini" File, and find this section of code:

+AllowedClasses = "Grenadier"
+AllowedClasses = "Ranger"
+AllowedClasses = "Sharpshooter"
+AllowedClasses = "Specialist"

You will want to copy this specific line for a Modded Class you wish to add, for my example, I will use Aranador's "[WOTC] Trooper Class" https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1722717047, to find out what the Code Name for the Trooper Class is, we need to go to the Mod Folder for this Modded Class.

STEP THREE: To find the correct folder, you will need to know the Workshop Mod's "Page Number", currently you can find this number at the end of the Web Link that is colored in green on the top left of the Steam Tab when you are on a Workshop Page for a specific Mod. In this case, Aranador's Trooper Class Workshop Page Number is "1722717047"

You will need to find the corresponding number in the "Steam/Steamapps/Workshop/Content/268500" Folder, the same one you found the Mod files for every other Mod in XCOM 2 you have installed. Upon finding the correct folder, go to the Config file for Aranador's Mod.

Now you must open "XComClassData.ini", as this folder contains the code that corresponds to the Trooper's Class in-game. Upon opening the file, find this segment of code, often located at the top of the file:

[XComGame.X2SoldierClass_DefaultClasses]
+SoldierClasses="ARATrooper"

Now you must simply copy, "ARATrooper", be sure to remember putting in the correct capital letters in the code. DO NOT COPY "+SoldierClasses=", only copy the Class' ID

STEP FOUR: Now go back to the "XComUtilitySlotPsionicsWOTC.ini" folder, open it and go back to this section of code:

+AllowedClasses = "Grenadier"
+AllowedClasses = "Ranger"
+AllowedClasses = "Sharpshooter"
+AllowedClasses = "Specialist"

Now copy the "+AllowedClasses =" line of code, and add in Aranador's Trooper Class' code ID, like this:

+AllowedClasses = "ARATrooper"
+AllowedClasses = "Grenadier"
+AllowedClasses = "Ranger"
+AllowedClasses = "Sharpshooter"
+AllowedClasses = "Specialist"

This should now make it so that Aranador's Trooper Class is now able to be a valid unit which can gain Psionic abilities in Psionic Training, follow/repeat this process with other Modded classes you wish to enable and add into Psionic Training. This is a rough guide and it's here primarily to help people who wanted modded classes able to use this Mod as well.