AWS DMS Failed Connection to On-Premises MySQL as Source DB

I am currently involved in a scenario where I need to migrate my client's on-premises MySQL database data to AWS DynamoDB tables. To accomplish this task, I have set up a successful connection for the DynamoDB table (target) using AWS DMS.

However, I'm facing an issue when trying to connect to the on-premises database. The test endpoint connection always fails, and the error message indicates the problem. Interestingly, I can connect to the on-premises database through MySQL Workbench using the same set of credentials that I used for the endpoint.

To address this problem, I have already taken some steps. I created a route table and allowed traffic from the internet to the replication instance. Despite these efforts, the issue persists. If anyone has any suggestions or insights on how to resolve this, I would greatly appreciate your help.

Error Message : Test Endpoint failed: Application-Status: 1020912, Application-Message: Cannot connect to ODBC provider ODBC general error., Application-Detailed-Message: RetCode: SQL_ERROR SqlState: HY000 NativeError: 2003 Message: [MySQL][ODBC 8.0(w) Driver]Can't connect to MySQL server on 'SERVER IP ADDRESS' (111)

I also referred the below article (Configuration for a network to a VPC using the Internet) https://docs.aws.amazon.com/dms/latest/userguide/CHAP_ReplicationInstance.VPC.html

Thank you in advance.