Camon im send btc to you first, then you pay bitpay invoice. There is no address in that invoice, just barcode. I tried scan this via blockchain wallet and says invalid bitcoin address.
Are you sure that it's a bitcoin address? Send me a message; I don't know why this is posing a problem for you, but if you send the bitcoin to this address I just generated, I'll pay the invoice for you, as there's potentially zero risk for me.
BTC (SegWit-enabled) address: 321UMwRKJ3DyzqDXHJxeJSyVVys8RCxpjU
Send me a private message here with a link to the bitpay invoice once you send the $15 in BTC so that I get an email notification and make the transaction for you.