Why are my Yeelight Smart LED M2 bulbs offline?

I’m having trouble installing my new Yeelight Smart LED M2 color bulbs. I downloaded both the Yeelight app and the Xiaomi Home and and the Google Home app. First I opened the Yeelight app and followed the instructions as to how the app would be able to find the bulbs. The app found my bulbs and I connected them and also connected them in my bluetooth. But I can’t control them because the app says that they are offline. I tried connecting them in the Xiaomi Home app and the Google Home app, but they couldn’t find the bulbs. I tried deleting the bulbs from the Yeelight app and tried again on the other apps, but it still doesn’t work. What am I supposed to do now? Can anybody help please?

Do you have a Bluetooth gateway?