PostgreSQL DB Secure Link Established but connection error encountered, please help

Hi Yukian - The remote certificate is invalid according to the validation procedure typically occurs when there are SSL/TLS certificate issues between Power BI and the PostgreSQL database.

Modify the SSL mode in your connection string

sslmode=require

Ensure the SSL certificate installed on your PostgreSQL server is valid:

1.It should be issued by a trusted Certificate Authority (CA).

2.The common name (CN) or Subject Alternative Name (SAN) in the certificate must match the PostgreSQL server’s hostname or IP.

Use tools like pgAdmin or psql with the same connection settings to confirm the database accepts SSL connections.

PostgreSQL: Documentation: 17: 18.9. Secure TCP/IP Connections with SSL

PostgreSQL: PostgreSQL Mailing List Archives

Hope the above details helps.

Hi Yukian ,
Thank you for reaching out to the Microsoft Fabric Community Forum regarding the issue you're experiencing.

In addition to the helpful response provided by rajendraongole1 , I would like to share a document that may assist you. 
Complete guide to setting up Power BI connecting to PostgreSQL.

Hope this post helps you. If so, kindly  accept it as the solution so that it can assist other members and help them find the answer more quickly.