Add Text Attribute Type For Customers to submit link with order

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I need to be able to allow customers to submit an order with filled out text field with their orders

For instance I'll have a site that does reports on Instagram profiles that the user pays for: I want them to be able to submit their username, or profile link, or anything else as a text submission with their order. 

I understand that there's a trick with using customization to do this, but I want to be able to use attributes so that I can map it properly/uniquely.

@vekia - I saw your example here: https://mypresta.eu/en/art/developer/new-field-product-backoffice.html

That seemed like it is heading in the direction that I need to go in, but I'm using the latest version of prestashop and I think far too much has changed since that post for that to work.

I know there's a module that covers this but I don't want to/can't spend $250-300 on a module just to add new attribute types.