Serialize QuerySet to JSON with FK DJANGO

I want to send a JSON of a model of an intersection table so I only have foreign keys saved, I tried to make a list and then convert it to JSON but I only receive the ids and I need the content, I also tried in the back as a temporary solution to make a dictionary with the Queryset but the ‘<>’ makes it mark an error in the JS, does anyone know a way to have the data of my foreign keys and make them a JSON?

models:

class Periodos(models.Model):
    anyo         = models.IntegerField(default=2022)
    periodo      = models.CharField(max_length=10)
    fecha_inicio = models.DateField(blank=True, null=True)
    fecha_fin    = models.DateField(blank=True, null=True)
    class Meta:
        app_label = 'modelos'
        verbose_name = u'periodo'
        verbose_name_plural = u'Periodos'
        ordering = ('id',)
    def __str__(self):
        return u'%s - %s' % (self.anyo,self.periodo)

class Programas(models.Model):
    programa  = models.CharField(max_length=255,blank=True, null=True)
    activo    = models.BooleanField(default=True)
    class Meta:
        app_label           = 'modelos'
        verbose_name        = u'Programas'
        verbose_name_plural = u'Programas'  
    def __str__(self) -> str:
        return self.programa


class Programa_periodo(models.Model):
    periodo     = models.ForeignKey(Periodos, related_name='Programa_periodo_periodo',on_delete=models.CASCADE)
    programa    = models.ForeignKey(Programas, related_name='Programa_periodo_Programa',on_delete=models.CASCADE)
    
    class Meta:
        app_label           = 'modelos'
        verbose_name        = u'Programa Periodo'
        verbose_name_plural = u'Programa Periodo'  

    def __str__(self) -> str:
        return self.programa.programa

py where i send data

def iniciativa(request):
    if request.user.is_authenticated:
        context                    = {}
        
        context['marcas']          = json.dumps(list(Marcas.objects.values()))
        context['eo']              =  get_estructura_org()
        
        #This is where I call the data 
        programa = Programa_periodo.objects.all()
        
        #These two only return the ids
        # context['programa_periodos'] = json.dumps(list(Programa_periodo.objects.values()))
        #context['programa_periodos'] = serializers.serialize("json", Programa_periodo.objects.all())

        #One of my try but fail for the '<>'
        programa_periodo = {} 
        for pg in  programa:
            programa_periodo[pg.periodo] = pg.programa
                    
        context['programa_periodos'] = programa_periodo
        
        return render(request, 'agregar_iniciativa.html', context)
    else:
        return HttpResponseBadRequest('Favor de ingresar sesión en el sistema.', format(request.method), status=401)