This is just a reminder that this is a public forum, and you shouldn’t post connection details here. Although they are likely local connections, it is a good habit not to do it under any circumstances.
One thing I noticed, as I mentioned above, is that you are using localhost in your MySQL connection URL. I don’t think you would be running MySQL on the same Render instance as your Spring Boot service. You will need to run a separate MySQL that your Render service uses. If you don’t already have one, we have a guide to installing MySQL on Render here: https://docs.render.com/deploy-mysql.