geodjango | just another geodjango project

I am a django beginner and trying to programm a simple geo application. My setup: django/geodjango + leaflet. Everything works fine and geo objects (GeoObject) are displayed. But now I want to add aditional properties ("status") from another model and display them also via leaflet - but I´m stuck.

my models.py:

I have a table with a GeoDjango GeometryField, and records include both points and polygons. I need to return those records with Point geometry within a given distance in km from a given point, for an external API. I first filter for Point records, annotate those with a Distance object, then filter for distance.

I find the generation of the filtered queryset fed to the serializer works fine in my IDE. But when I run the view, it hangs on the annotate() step, with this error:

I'm trying to get a django project up and running, which depends on GDAL library. I'm working on a M1 based mac.

Following the instructions on official Django docs, I've installed the necessary packages via brew

We've developed a responsive map using this tutorial where Django Rest Framework serves responses that populates the map. My viewsets.py:

Recently set up Leaflet map with GeoDjango / rest_framework_gis and have limited results with Pagination, but the result still seems to have Leaflet cumulatively processing every marker it receives, not just what's in view, which lags and eventually crashes browsers. In the comment I was advised to address this with JS. This makes sense as it's front end, but how can we do this?

The JS from this tutorial:

I've built basic Django mapping functionality through this tutorial but Python keeps blowing through 32GB of ram and/or the browser crashes, presumably because the query isn't limited to the first n results and the DB has millions of entries.

My "vietsets.py":

I'm learning how dockerize a Django project. So, I've created a simple hello world with Django. After this I've created my Dockerfile:

This appears to be a common error, and I have checked all the solutions I could find (there are only about 4 and almost all of them involve misconfigurations). I am NOT using heroku, but I AM using docker. I am using the docker images python:3.9.7 and postgis/postgis:10-3.1-alpine. My Dockerfile contains the following line:

We're getting "django.core.exceptions.ImproperlyConfigured: Could not find the GDAL library", GeoDjango's common installation issue.

Dev environment is Win10 and GDAL libraries were resolved following this answer on the same question for windows, which supplies filepaths directly. I now can't deploy because prod is Ubuntu 20.04 and that answer doesn't address how to resolve on Ubuntu.

I'm new to Ubuntu / Linux and I think I've installed GDAL with sudo apt install libpq-dev gdal-bin libgdal-dev following these instructions, but Django doesn't know how to find the libraries nor do I. This question mentions "GDAL_LIBRARY_PATH = '/usr/local/lib/libgdal.so.1.15.1'", but my "/usr/local/lib/" only includes the dirs of python3.8 and 3.9.

Also, unsure if relevant but I'm deploying on Dokku, and am unsure if containerizing things precludes Django from finding libs outside of Dokku's fancy ecosystem I don't well understand. This post is the only other post mentioning both Dokku and GDAL, and although it asks something unrelated its requirements.txt includes "GDAL==2.4.1". Could we somehow resolve this by supplying it in a similar way?

What simple thing am I missing or doing wrong?