How to input address into the message in dogecoinrpc?

Question

I'm new to python and there are barely any tutorials or documentation on this. When I do getnewaddress("label"), I can set the label but can't create a new "message", plus these newly created addresses through the python script and debug console do not get displayed in GUI, I can only see them through console. enter image description here My idea was to make an ecommerce website where people sell and buy products. When someone creates an account, it will generate a new address for that seller on back-end, while his real address that he inputs into the website will go to "Message" tab, and from that message tab it grabs the address and forwards dogecoins to it. It would go into the generated wallet on my end first, take 2% fee and send rest of 98% coins to the wallet in the "Message" tab, but when I do "getnewaddress", I can't input the real address into the message tab, I can only assign a label but it'd be used for seller's nickname on the website. Sorry for noobdy questions, but would be very grateful if you told if there's anyway to create a new address with a message, and if it's possible to display all that on the front-end. Thank you