Hi Alan & welcome to the site.
I think what The Cptn means is that to qualify to enter the competition, you have to have at least 10 posts on the site here.
Unless your mix is uploaded to the site player and playable on it, your mix won't qualify to enter the comp. For that to happen you need to engage somewhat with the community here and have a minimum amount of posts.
By the looks of things you have 2 posts now, so I'm sure another 8 won't be a hardship.
All the best with your mix!