You don't need permission

You don't need permission to write the highest quality code you can. You don't need permission to design a reliable server architecture that won't crash. You don't need permission to develop a suite of tests to ensure bugs are caught early. You don't need permission to upgrade your dependencies, to ensure your system stays secure and modern.

Your boss, manager or client will never ask you to take time to refactor your code. They'll never ask you to set up a test suite for the code you wrote. They'll never ask you to upgrade your framework.

It's not that they don't want you to do things to improve the quality of the code. It's because they expect you to write high quality code from the start. They believe you to know what it takes to design a reliable system. They trust you to build web apps that last.

They'll never ask you to make sure your code has no bugs. They'll never ask you to make sure the new system doesn't crash. They'll never ask you to make sure your code will be understood by other developers. It all goes without saying.

So, don't put these things off for later. Don't put writing tests on the backlog. Don't put refactoring on your list of nice-to-haves. Don't put improving the reliability of your servers on the wishlist. Don't wait for permission.

Do these things every day. Make them a part of your process. You don't need permission.