Docker course, chapter Deploying Applications, topic Reducing the Image Size

Docker
1

In the video we are supposed to add

FROM nginx:1.12-alpine

to Dockerfile.prod, but then i got message during docker build:

------
 > [internal] load metadata for docker.io/library/nginx:1.12-alpine:
------
Dockerfile.prod:10
--------------------
   8 |     
   9 |     # Step 2: Production
  10 | >>> FROM nginx:1.12-alpine
  11 |     RUN addgroup app && adduser -S -G app app
  12 |     USER app
--------------------
ERROR: failed to solve: nginx:1.12-alpine: failed to resolve source metadata for docker.io/library/nginx:1.12-alpine: no match for platform in manifest: not found

even if this image is available on docker hub: LINK.

In the other hand when I change nginx image to nginx:1.27.0-alpine3.19, I got during docker run:

2024/07/06 11:41:46 [warn] 1#1: the "user" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:2
nginx: [warn] the "user" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:2
2024/07/06 11:41:46 [emerg] 1#1: mkdir() "/var/cache/nginx/client_temp" failed (13: Permission denied)
nginx: [emerg] mkdir() "/var/cache/nginx/client_temp" failed (13: Permission denied)

I got stuck, can someone help me please?