Unable to connect to Postgres DB due to the authentication type 10 is not supported

I solved similar issue by applying below steps in PostgreSQL Version 13 :

1. Change password_encryption to md5.

   File: C:\Program Files\PostgreSQL\13\data\postgresql.conf

   

2. Change scram-sha-256 to md5 in host settings.

   File: C:\Program Files\PostgreSQL\13\data\pg_hba.conf.

   host all all 0.0.0.0/0 md5

   

3. Change Password ( this restore password in md5 format).

   Example: ALTER ROLE postgres WITH PASSWORD 'root';

4. Make sure you set listen_addresses = '*' if you are working non production
   environment.

   File : C:\Program Files\PostgreSQL\13\data\postgresql.conf

Get your pg_hba.conf File in the Directory
C:\Program Files\PostgreSQL\13\data\pg_hba.conf

And Simply Change scram-sha-256 under Column Method to trust.

It worked For me!

According to the wiki, the supported JDBC driver for SCRAM-SHA-256 encryption is 42.2.0 or above.
In my case, the driver was 41.1.1. Change it to 42.2.0 or above. That fixed it for me.

(Maven, pom.xml):

<dependency>
    <groupId>org.postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>42.2.0</version>
</dependency>

By setting password_encryption to scram-sha-256 (which is the default value in v13) you also get scram-sha-256 authentication, even if you have md5 in pg_hba.conf.

Now you are using an old JDBC driver version on the client side that does not support that authentication method, even though PostgreSQL introduced it in v10, three years ago.

You should upgrade your JDBC driver. An alternative would be to set password_encryption back to md5, but then you’ll have to reset all passwords and live with lower security.