Your video must be posted from the account you applied with.
Every job keeps the social account you applied with. Your reward is tied to that account's views, so the video you send as proof must be published from that account. A video from a different account cannot be paid, and the Brand cannot change that. If you want to use another account, add and verify it first, then apply to new work with it - your existing jobs stay with the account they were applied with.
You applied with @yourname, so post the video on @yourname.
Our support team can explain anything in plain language.