How appropriate is invoice certification?

540000/1.17 * 0.17 = 78461.54 This amount is the value-added tax you have to pay this month.

Then how do I calculate how many votes I have certified?

You only need to calculate your input invoice tax. The above amount is enough, and it doesn't matter if it is more, because it can be deducted until next month. You must remember that your input invoice should not exceed 180 days, which will be overdue.

I mean, what is the total amount of invoices received for certification?

If the tax rate of all special VAT tickets you receive is 17%, then the total amount of certified special VAT tickets is the same as 540,000, which can only be greater than this amount, but not less than this amount. If it is less than this amount, you will have to pay VAT.