Obviously, some extra check would be performed after the user hit the Submit button.

显然，用户点击提交按钮后，会进行一些额外的检查。

youdao

I know that they are going to extra check my harness.

VOA: standard.2010.07.26

So, if you pay your entry fee and then write an extra check, deduction on the extra.

FORBES: Run With It: Sports, Races and Taxes

Ministers are examining if the extra check could "reduce the risk to domestic violence victims", she said.

BBC: UK Politics

"As reluctant as many pharmacists and consumers are to take the extra time, it is worth one last extra check to make sure nothing will go wrong, " says Michael Negrete, chief executive of the Pharmacy Foundation of California.

WSJ: When 'Use Only as Directed' Isn't Easy