Installation of aiven-extras feature to Postgres running in docker container [help wanted]

[Jurajzovinec]

Hello,
I am asking for help with the installation of aiven-extras extension to database which is running in docker container. I am trying to dump some data from the staging database (running on digital ocean) to my local db which is running using Postgres docker image
Apparently, aiven-extras extension is installed on the staging database (which is running on digital ocean) and this extension is not a part of Postgres docker image.
Error thrown during docker build:

2023-08-01 05:24:14.374 UTC [51] ERROR:  extension "aiven_extras" is not available
2023-08-01 05:24:14.374 UTC [51] DETAIL:  Could not open extension control file "/usr/local/share/postgresql/extension/aiven_extras.control": No such file or directory.
2023-08-01 05:24:14.374 UTC [51] HINT:  The extension must first be installed on the system where PostgreSQL is running.

This error is triggered by one of these lines in schema.sql file

--
-- PostgreSQL database dump
--

-- Dumped from database version 15.3
-- Dumped by pg_dump version 15.3

-- Started on 2023-07-31 19:43:44 UTC

SET statement_timeout = 0;
SET lock_timeout = 0;
SET idle_in_transaction_session_timeout = 0;
SET client_encoding = 'UTF8';
SET standard_conforming_strings = on;
SELECT pg_catalog.set_config('search_path', '', false);
SET check_function_bodies = false;
SET xmloption = content;
SET client_min_messages = warning;
SET row_security = off;

--
-- TOC entry 6 (class 2615 OID 16985)
-- Name: aiven_extras; Type: SCHEMA; Schema: -; Owner: postgres
--

CREATE SCHEMA aiven_extras;


ALTER SCHEMA aiven_extras OWNER TO postgres;

--
-- TOC entry 2 (class 3079 OID 16986)
-- Name: aiven_extras; Type: EXTENSION; Schema: -; Owner: -
--

CREATE EXTENSION IF NOT EXISTS aiven_extras WITH SCHEMA aiven_extras;


--
-- TOC entry 4611 (class 0 OID 0)
-- Dependencies: 2
-- Name: EXTENSION aiven_extras; Type: COMMENT; Schema: -; Owner: 
--

COMMENT ON EXTENSION aiven_extras IS 'aiven_extras';

PS: I generated the schema.sql file by this line in my Dockerfile

RUN PGPASSWORD=${PROD_DB_PASSWORD} pg_dump --verbose --no-privileges -U doadmin -h ****.b.db.ondigitalocean.com -p 25060 -s core > /docker-entrypoint-initdb.d/schema.sql