Add charge when installment plan term is printed

Hi Experts,

I need to add a charge on installment plan term letter whenever it is printed.

I dont want to add a charge on installment plan when it is created.

Charge /Fixed price should be applicable and charged only when a term letter is printed.

It should be also displayed in letter.

Is there configuration change available for this requirement.

How it can be achievable ?

Thanks & Regards,

Nachiket