Thank you for your reply.

You can answer: it is fate to build a platform for everyone, and everyone is destined to get together. I hope everyone will cherish the fate and thank the group administrators for their support. When others say thank you, you must first make clear why they say thank you. If it's because of some daily chores, it's ok to respond formally to each other. If it is because something important involves gratitude, you should organize appropriate language to make the other person feel that you have accepted his gratitude without causing psychological pressure.