Amazon SES + Sendy - TLS 1.2 AWS API endpoints update required

I have a droplet that I installed 10 years ago on DigitalOcean with Ubuntu 13.04 x64 following a beginner's tutorial. It has the VestaCP control panel version 0.9.8 installed. I only have the Sendy email client installed on that server, which uses the credentials of the Amazon SES service to send emails. Sendy is also updated to the latest version 6.0.5.

I received an email from Amazon with this subject: [ACTION REQUIRED] - Update your TLS connections to 1.2 to maintain AWS endpoint connectivity [AWS Account: xxxx]

The content of the email states that I have a deadline of June 28, 2023, and at the end of the email, it says:

Please see the following for further details on the TLS 1.0 or TLS 1.1 connections detected from your account between March 17, 2023 and April 3, 2023:

Region | Endpoint | API Event Name | TLS Version | Connection Count | UserAgent us-east-1 | sns.us-east-1.amazonaws.com | ListSubscriptions | TLSv1.1 | 10 | N/A us-east-1 | email.us-east-1.amazonaws.com | GetSendQuota | TLSv1.1 | 10 | SimpleEmailService/php us-east-1 | sns.us-east-1.amazonaws.com | CreateTopic | TLSv1.1 | 20 | N/A us-east-1 | sns.us-east-1.amazonaws.com | Subscribe | TLSv1.1 | 20 | N/A us-east-1 | email.us-east-1.amazonaws.com | GetIdentityVerificationAttributes | TLSv1.1 | 20 | SimpleEmailService/php us-east-1 | email.us-east-1.amazonaws.com | SetIdentityFeedbackForwardingEnabled | TLSv1.1 | 20 | SimpleEmailService/php us-east-1 | email.us-east-1.amazonaws.com | SetIdentityNotificationTopic | TLSv1.1 | 20 | SimpleEmailService/php us-east-1 | email.us-east-1.amazonaws.com | ListIdentities | TLSv1.1 | 20 | SimpleEmailService/php

I have no idea what I need to do or if it's related to Linux, Vesta, Sendy, or the Amazon SES account. I have a domain associated with the Sendy installation that doesn't have an SSL certificate installed. Could this be related to it? I have been using the http:// protocol without any problems since the beginning.

I searched within other users' questions but couldn't find the answer. Please, I would appreciate it if someone could guide me, at least, to know which way I need to keep investigating.

Thank you very much.