Why receive adress is diffrent between my insert adress?
The wallet has many addresses, both are okay and you have control over both and over any address your wallet used in the past.
Which adress should i pay BTC?
If you mean where to send the micropayment to link a BTC address, then the transition bot tells you everything. To link, you have to chat with it, go to
byteball.org and click on transition bot, it will get paired with your device, the bot will give you instructions to link your address.
If you are talking about something else, can you please clarify?