I want to automate BITCOIN payments and I need to make a donate button that sends an additionally OP_RETURN parameter with the value of the encrypted order id. I just want to send a small message with the payment. I have documented myself a little bit and I saw that the OP_RETURN parameter may help me. How do I make that happen? Is there a wallet that does that or Do I have to do it from bitcoin-cli?
I also want to make this in PHP. I mean I need a button that will make a payment with that encrypted order id.
Thanks for your advice in advance.