Populate Input Field using FormControl Angular

First of all, I suggest you re-think your approach as mentioned in the earlier comment it seems you have made it unnecessarily complicated. Also, I would think of renaming your variables it is quite confusing and will be a pain to maintain later on.

To answer your question and get the "ion-input" printed on the screen do the following changes to the HTML.

You can not assign <div [formGroupName] = "i"> i to the formGroup since it is not of type formGroup as it is assigned to the index.

The solution is to assign <div [formGroupName] = "insuranceCompany[0]"> So that a form group will be assigned. Again I suggest that you rename the variable "insuranceCompany" for clarity purposes as there is a control named "insuranceCompany" as well.

Here is a working example of your code minus the ionic tags. https://stackblitz.com/edit/angular-ivy-b3gtly?file=src/app/app.component.ts

Hope I made myself clear, and hope it helps.