How to write the clause of issuing special VAT invoice in the contract?

This is usually written in the "payment terms"

You can specify whether to pay first or later.

When to provide the invoice, after or before receiving the last payment, and so on.

Is the invoice type provided a special VAT invoice or an ordinary invoice, and what is the tax rate?

In addition, it must be clearly stated whether the contract price includes tax.

So that when the time comes, ask the other party to issue an invoice, and the other party will ask you to pay another tax point.