Instantiating and/or prefilling django model forms

Question

I am building my first Django application, a 'simple' web-based withdrawal and deposit system. A user's items are stored in an "Items" class:

(models.py)

class Item(models.Model):
owner = models.ForeignKey(User, on_delete=models.CASCADE)
title = models.CharField(max_length=100)
stock = models.IntegerField()
def __str__(self):
    return self.title

Each "Cart" item is stored as an "OrderItem":

(models.py)

class OrderItem(models.Model):
item = models.ForeignKey(Item, on_delete=models.CASCADE)
quantity = models.IntegerField(default=0)
def __str__(self):
    return self.item.title

To add items to their cart, users will go to a page that displays all of their items in forms, which they can fill and click the "Add to cart button" to create that OrderItem.

(forms.py)

class OrderItemForm(ModelForm):
class Meta:
    model = OrderItem
    fields = ["quantity", "item"]

The problem that I am having with this approach is that I need many OrderItem forms, with their "item" variable prefilled OR somehow instantiating said value. In other words, I don't want the approach Django provides by default with a dropdown, i need each of those dropdown items rendered as separate forms.

(storage.html)

<div class="row">
<div class="col-md-9">
    <div class="row">
        {% for i in items %}
        <div class="card">
            <img src="static 'demo/logo.png" class="card-img-top">
            <h5 class="card-title ml-2">{{i}}</h5>
            <form class="form-inline" method="POST"> {% csrf_token %}
                <div class="form-group ml-2 mb-2">
                    {{form.quantity}}
                    <input type="submit" class="btn" value="Add to Cart">
                </div>
            </form>
        </div>
        {% endfor %}
    </div>
</div>

As you can see, my solution to this problem has been creating a for loop inside my html template that displays these forms, but I am at a loss in which way I can pass the "i" instance to the "form.item" in this way. All the info I've found online assigns some form variable a default value, but that wouldn't work with what I'm trying to accomplish... Maybe tackling this from the html level is not a good solution but I am quite lost at this point.

Thanks!