Custom Calculator for Fluent Forms Plugin

Hello, I need to insert a calculator into the order form so that it calculates the amounts in CZK and shows the final price directly in the order summary.
​plugin FLUENT FORM
The calculator will let the customer:

Choose the type of Club (Silver, Gold, Platinum).
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Choose the length of membership: 1 month, 3 months (5% discount), 6 months (10% discount), or 1 year (12 months, but the price is only for 11 months – 1 month free).
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Immediately see the resulting price in CZK for the selected combination, calculated from the base monthly price and discounts:

Silver Club: 1950 Kč per month.
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Gold Club: 2730 Kč per month.
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Platinum Club: 3510 Kč per month.
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The calculator must:

Use Fluent Forms calculation features so that the final price is updated in real time when the user changes the club or period.

Show the full amount in CZK in the order (and optionally also a breakdown: base price, discount, total).

Respect the preset prices for all options, for example:

3 months = 3 × monthly price − 5% discount.

6 months = 6 × monthly price − 10% discount.

12 months = 11 × monthly price (1 month free).

Transfer the calculated total price into the order (and possibly to the payment field) so that the customer pays exactly the amount computed by the calculator.
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I am currently using the Fluent Forms plugin because of the design of the forms and for future integrations, so the calculator should be implemented as part of this plugin using its numeric/calculation fields and payment fields.

Regarding timing: I would like to have this ready within a few days; ideally we can go over the details and your availability tomorrow or by Friday, so that implementation and testing can be completed this week.