This will depend on your local laws. If VAT is a tax to be paid by you as the end user, and there is no method of recovering the tax, it is simply part of the purchase price of whatever you bought. So enter the tax-inclusive amount.
If VAT is recoverable under your tax laws for some reason (small business stimulus, special category of equipment, or something), add it as a line item allocated to a separate expense account so you can report it on your tax filing.
If VAT you pay can be offset against VAT you collect from others, select the proper tax code and mark it as tax-inclusive and Manager will post the amount to the
Tax payable account. Or mark the unburdened price as tax-exclusive, mark the tax code, and Manager will add it for you.
There are many discussions of VAT on this forum. Search for them.