asyncpg error: “no pg_hba.conf entry for host” in Heroku

I'm using asyncpg to connect my database in Heroku postgresql, using python:

import asyncpg

async def create_db_pool():
   bot.pg_con = await asyncpg.create_pool(dsn="postgres://....", host="....amazonaws.com", user="xxx", database="yyy", port="5432", password="12345")

it was working perfectly until I received an email from heroku advising me of a maintenance:
Maintenance (DATABASE_URL on myappname) is starting now. We will update you when it has completed.

then this error appeared:

asyncpg.exceptions.InvalidAuthorizationSpecificationError: no pg_hba.conf entry for host "123.456.789.10", user "xxx", database "yyy", SSL off

I tried to follow some help, like putting ssl=True but this error appeared:

ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate (_ssl.c:1108)

same as putting ssl="allow"

asyncpg.exceptions.InvalidPasswordError: password authentication failed for user "xxx"

what can I do to fix this?

https://stackoverflow.com/questions/62053185/asyncpg-error-no-pg-hba-conf-entry-for-host-in-heroku

プロジェクトファイルやテストは指定されていません。まず asyncpg.create_pool の呼び出し、Heroku PostgreSQL のメンテナンス通知、3 つの接続エラーを調査し、失敗が asyncpg で再現可能なのか、それとも Heroku データベース設定に固有なのかを判断してください。完了の基準は、接続結果が検証済みであることです。