customfield Add custom text field for each product combination in Prestashop 1.7

[swapnilphanse]

I am new to Prestashop and in the project on which I am currently working, I need to add a custom text field in the product combination page. This field should be visible in all the product combination admin page where I can input some data along with the rest of the fields like. What I am trying to accomplish with this is, the products will be sold based on the floor area covered. For eg. 1 quantity of product can cover area of 5.85 square meters. The customer will input their floor area and as per the entered area quantity will be calculated automatically. I have done this part but the part where I am stuck is, the area covered by different product will be different. It will not be same for every product so I need to add a custom field in combination where I can enter the specific area covered by that particular product in 1 quantity so when any customer enters their floor area they get the needed quantity of that particular product.  Can please someone guide me with this.