AttributeError: 'bool' object has no attribute 'last'

Hi, I am having trouble when I want to make a second post.

File "/posts/models.py", line 37, in upload_location
new_id = 1
qs = PostModel.objects.order_by("id").exists()
if qs:
new_id = qs.last().id + 1
AttributeError: 'bool' object has no attribute 'last'

Can anyone help me with this?