How to insert and calculate the amount ttc in sqlserver

Question

Hi friends ,

I have three table Countdown, Walk, Bon de reception

The Id_marche is a foreign key in the countdown table and

The Receipt table contains the Id_marche

I want to insert in recordings in the counting table which contains Amount TTC so to calculate Amount TTC = TVA* Amount HT

I have the TVA  AND the Amount HT in the voucher table of reception

I could not create a request to insert and calculate the amount TTC

I do not know is what I described well my condition but hey I will screenshot the three table and you will see the relationship between them

And thank you for you in advance