You can upgrade or update your current Magento version to a specific higher version using composer and command line.
You can even simplify your upgrade through professional Magento 2 Upgrade Services .
For that, you have to open terminal/command prompt.
After that go to you’re Magento site’s root directory in the terminal using cd command
Know More: https://webkul.com/blog/upgrade-magento2-via-command-line/