Is it appropriate do say "Because there was no answer, I end our class"?
In this case you decide not to have a class, because no students connected for this class.I work as an ESL teacher at a Language Center in Brazil. During the pandemic, I've been teaching online. Ten minutes before the lesson starts, I greet the students using WhatsApp and share a link for everyone to connect to Zoom. Sometimes no student answers my greetings, so I just send them a message, like "Because there was no answer, I end our class".