I've asked this question elsewhere but I'll ask again here, maybe I will get some better advice.  So, I purchased bitcoin via coinmama, and can see that the funds were transferred to my bitcoin wallet in blockchain, but in a "watch only" address. The problem is when I try to access the funds in this address, i'm being asked for a private key. Or when I try to transfer funds to my wallet I get this message:

"Archive swept addresses? 0 address was successfully transferred to My Bitcoin Wallet. Would you like to archive this address now?"

What am i doing wrong? This is the 3rd time i've purchased bitcoin through coinmama and the first 2 transactions were fine. This "watch only" address is completely new to me. Now I need to provide the correct private key so I can move the funds to my wallet. Can someone PLEASE tell me how I can find my private key? From the research that I've done, it was as simple as clicking on addresses>more options>import/export and from there one would be able to get the private key, but on the latest version of blockchain there is no import/export tab. I've contacted blockchain support asking them how I can find my private key and they've told me there was no way of them knowing my private key (duh!) nor do they know how I can retrieve it. I know my 12 word backup phrase as well. It's frustrating to see 90% of my bitcoins in a "watch only" address that I can't even touch. There's got to be a way. Someone please HELP! Thanks in advance