[UE4.26] File and Folder Management, Create, Find, Delete

DeleteFile

bool UBPLibrary::DeleteFile(FString Path)
{
IPlatformFile& FileManager = FPlatformFileManager::Get().GetPlatformFile();
return FileManager.DeleteFile(*Path);
}

DeleteDirectory

bool UBPLibrary::DeleteDirectory(FString Path)
{
IPlatformFile& FileManager = FPlatformFileManager::Get().GetPlatformFile();
return FileManager.DeleteDirectoryRecursively(*Path);
}

Reference Link: 
File and Folder Management, Create, Find, Delete