For such error, the first thing to check, is to google undefined type like ue5 UGameplayTagsManager and find doc about it: UGameplayTagsManager | Unreal Engine Documentation
Here you can see, that the required header is
#include "GameplayTagsManager.h"
which we probably missed.
Also probably you missing a module GameplayTags in your *.build.cs file. Add it to PublicDependecyModuleNames, so this part of file would look similar to this:
PublicDependencyModuleNames.AddRange(new string[]
{
"Core",
"CoreUObject",
"Engine",
"GameplayTags",
});
And then try compile project again