How can I apply etag?

Do you have etag middleware?

Hello! Anybody here? I would also like to receive a response to this question? Or should I create a fresh thread to get visitors and finally a response? I am from https://worldcams.tv/netherlands/amsterdam/dam-square. In my location, nobody is using this information so I have no one to consult. I will still try to find something on the other threads. I will keep you updated.