I am trying to use the result of a selection as input to another selection. I have been working on this for three weeks, and I cannot find a simple answer.

Here are my models:

from django.db import models

# Create your models here.
class School(models.Model):

        id = models.CharField(primary_key=True, max_length=10)
        school_name = models.CharField(max_length=80)

        def __str__(self):
                return(f"{self.id} {self.school_name}")
                return self.id

        class Meta:
                ordering = ['id']
                indexes = [
                models.Index(fields=['id', 'school_name']),
                ]

class Courses(models.Model):

        id = models.CharField(primary_key=True, max_length=12)
        created_at = models.DateTimeField(auto_now_add=True)
        school = models.ForeignKey(School,  on_delete=models.PROTECT, related_name='school')
        name = models.CharField(max_length=150, null=True, blank=True)
        cost = models.CharField(max_length=75, null=True, blank=True)

        class Meta:
            ordering = ['id']
            indexes = [ models.Index(fields=['school']), models.Index(fields=['name', 'id'])]

        def __str__(self):
            return(f"{self.school} {self.name}")
            return self.name

class Student(models.Model):

        course = models.ForeignKey(Courses,  on_delete=models.PROTECT)
        created_at = models.DateTimeField(auto_now_add=True)
        student_id = models.CharField(max_length=20, null=True, blank=True)

class Meta:
        ordering = ['course']
        indexes = [
        models.Index(fields=['course']),
             
        ]

And my views:

def choose_school3(request):
    
    if request.user.is_authenticated:

        aschool = Courses.objects.all()
        form=SelectSchoolForm(request.POST)
        if request.method == "POST":
            if form.is_valid():
                data = form.cleaned_data
                choice = data['school']
                selected_school = Courses.objects.filter(school=choice).values()
    
                context = {'choice': choice}
                return render(request, 'add_student2b.html', context)
        context = {'form': form, 'aschool':aschool}  
        return render(request, 'choose_school3.html', context)  
    else:
        messages.success(request, "You Must Be Logged In To View Records!")
        return redirect('main')

def add_student2b(request, choice):

        chosen_school = Courses.objects.filter(school=choice).values()

        form = AddStudentForm(request.POST)
    
        context = {'form':form, 'choice':choice, 'chosen_school':chosen_school}
        return render(request, 'add_student2b.html', context)

def add_student5(request, pk):

    if request.user.is_authenticated:
        choice = School.objects.get(id=pk)
        courses = Courses.objects.filter(school=choice)
        
        form = modelformset_factory(Student, fields=['course','student_id'], formset=AddStudentForm2FormSet)

        context = {'courses':courses, 'choice':choice, 'form':form}
    
        return render(request, 'add_student5.html', context)

    else:
        messages.success(request, "You Must Be Logged In To View Records!")
        return redirect('main')

The forms:

class SelectSchoolForm(forms.ModelForm):

    class Meta:
            model = Courses
            fields = ('school', )
            labels = {'school':'School', }
            widgets = {'school': forms.Select(attrs={"placeholder":"School", "class":"form-select"}),

             }

class  AddStudentForm(forms.ModelForm):


    class Meta:
                model = Student
                fields = ( 'student_id', )
                labels = {'student_id':'',}
                widgets = {'student_id':forms.widgets.TextInput(attrs={"placeholder":"Student ID", "class":"form-control"}),
               
                }

class AddStudentForm2FormSet(BaseModelFormSet):


            def __init__(self, *args, **kwargs):

                super().__init__(self, *args, **kwargs)
                self.fields['course'].queryset = Student.objects.filter(all)

and html:
choose_school3.html:

<form class="row g-3" action="{% url 'choose_school3' %}" method="POST" enctype="multipart/form-data">
    {% csrf_token %}
<div class="col-md-6">
    
    
    {{ form.as_p }}
    
</div>

<div class="col-md-6">
<button type="submit" class="btn btn-secondary">Choose School</button>

<a href="{% url 'school' %}" class="btn btn-success">Back</a>
</div>

</form>

add_student2b.html:

<form class="row g-3" action="{% url 'choose_school' %}" method="POST" enctype="multipart/form-data">
    {% csrf_token %}
<div class="col-md-6">
    
    
    {{ form.as_p }}
    
</div>

<div class="col-md-6">

<a class="btn btn-secondary btn-lg" href="{% url 'add_student5' choice.id  %}" role="button">Add Student</a>

<a href="{% url 'school' %}" class="btn btn-success">Back</a>
</div>

</form>

and add_student5.html:

<form class="row g-3" action="{% url 'choose_school' %}" method="POST" enctype="multipart/form-data">
    {% csrf_token %}
<div class="col-md-6">
    
    
    {{ form.as_p }}
    
</div>

<div class="col-md-6">

<a class="btn btn-secondary btn-lg" href="{% url 'add_student5' choice.id  %}" role="button">Add Student</a>

<a href="{% url 'school' %}" class="btn btn-success">Back</a>
</div>

</form>

Everything I try sends me to an error. This most recent incarnation gives me this:

cannot unpack non-iterable builtin_function_or_method object

referring to the {{ form.as_p }} tag. I’ve been going in circles and down rabbit holes. Is it possible to do this with Django (and without JS or other things) or not? Please help.