Shipping method using collect points from the courier

[Inotex]

Hi, 

We would like to add an option for customers to select collect points of the courier on the checkout  -> shipping method.

If we can add this option, the customer can select the collect point in their area and take the parcel from the collect point in 2-4 days ( this is the time of the parcel that will stay on collect point).

If the customer select the collect points as shipping method, it must pay with credit card.

We talked to some shopify experts and they said we need an custom app but we know that Shopify doesn't accept modification on checkout page.

What must be done? 

The collect points must be shown like this: