error LNK2019: unresolved external symbol "public: bool __cdecl

2>LauroAnimInstance.cpp.obj : error LNK2019: unresolved external symbol "public: bool __cdecl ALauroCharacter::IsHoldingTheFlag(void)const " (?IsHoldingTheFlag@ALauroCharacter@@QEBA_NXZ) referenced in function "public: virtual void __cdecl ULauroAnimInstance::NativeUpdateAnimation(float)" (?NativeUpdateAnimation@ULauroAnimInstance@@UEAAXM@Z)
D:\UE-Genar\Genar\Binaries\Win64\Genar.exe : fatal error LNK1120: 1 unresolved externals

Hello I am learning to make a game from a course and suddenly having this error. In my online search I might not have included the right module in the build.cs? It is the same as the course but I am guessing that there are changes in ue 5.4?