OpenSea, page-81

Re transferring our Revv token from Opensea to Metamask. I just posted similar on FaceBook, so repeating here:

John Kennedy on 24/1 wrote:
William Hardstaff when you open opensea go to "account" then look up your "profile" this is where I found mine

I found mine following John's advice above. All good until I started transfer to Metamask.
Issues:
1. I got a message to say switch from Ethereum to polygon, so I clicked the link - then on Metamask, it said not enough funds - I hadn't figured on that, so unless anyone advises me differently, I will have to add some $ to Metamask first.
2. More importantly, Metamask warned me that (I think) my public address had changed. I stopped at that point, hoping for some help from John or others on this issue.
Any comments will be much appreciated