Django Forms: MultipleSelect with choices from another model (Foreign Key)

I'm trying to create a form where the user can select multiple technician. When I add the line technician = forms.SelectMultiple(label='Technicians Involved') to my forms.py I get a big blank box with no data. How can I populate that box with the technicians from the User model?

models.py

class Incident(models.Model):
    user_id = models.ForeignKey(User, related_name='user')
    technician = models.ForeignKey(User, related_name='technician')
    capa = models.CharField('capa number', max_length=9)

forms.py

class IncidentForm(forms.ModelForm):

    ###################### TRYING! ################################
    technician = forms.SelectMultiple(label='Technicians Involved')
    ###############################################################

    class Meta:
        model = Incident
        fields = [  'user_id',
                    'technician',
                    'capa',
                ]

views.py

def report_incident(request):

    template = "report.html"

    if request.method == 'POST':

        form = IncidentForm(request.POST)

        if form.is_valid():

            # Auto capturing logged in user
            incident = form.save(False)
            incident.user_id = request.user
            incident.save()
            return HttpResponseRedirect('/incidents/')
    else:
        form = IncidentForm() #an unbound form

        return render(request, template, {'form': form})

************** UPDATE WITH CORRECTIONS I MADE BELOW *********************

models.py

class Incident(models.Model):
    user_id = models.ForeignKey(User, related_name='user')
    technician = models.ManyToManyField(User, related_name='technician')
    capa = models.CharField('capa number', max_length=9)

forms.py

class IncidentForm(forms.ModelForm):

    technician = forms.SelectMultiple()

    class Meta:
        model = Incident
        fields = [  'user_id',
                    'technician',
                    'capa',
                ]

views.py No changes

admin.py Changes made to view multiple technicians per incident in the admin interface.

class IncidentAdmin(admin.ModelAdmin):
        list_display = ('id',
                        'user_id',
                        'capa',
                        'get_technicians'
                        )

       def get_technicians(self):
            return "\n".join([t.technicians for t in obj.technician.all()])


ANSWERS:


Try this out

class IncidentForm(forms.ModelForm):
   technician = forms.ModelMultipleChoiceField(widget=forms.CheckboxSelectMultiple(), queryset=User.objects.all())

     class Meta:
        model = Incident
        fields = [
                'technician',
                'capa',
               ]


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