This website ask me to enter the address FROM where I would be sending BTCs. But every time a send some BTC it seems to be sent out from a different address... Should I use the one I always see when I say I want to "receive" some BTC? Is it my "main" address?
1 Answer
There is no from
address in Bitcoin.
https://en.bitcoin.it/wiki/From_address
Each transaction reference an unspent output (UTXO)
that was sent to you in a previous transaction.
About the address, you need to generate a new one for each payment: https://en.bitcoin.it/wiki/Address