This depends on whether you are using Amazon Linux 1 AMI or Amazon Linux 2. For example, one of the currently supported Amazon Linux 2 AMI (ami-0a3c14e1ddbe7f23c) as noted in the Launch Wizard - provides Linux kernel version 4.14 which is also used by the last release of Amazon Linux 1. This is also slated for deprecation per this article so I'm assuming this is what you're referring to. To confirm, you can check if you are running Amazon Linux 1 or 2 via the console or through the instance itself with something like:
$ cat /etc/os-release
In the case of upgrading Amazon Linux 1 to Amazon Linux 2: per AWS Documentation, there is no way to directly upgrade the kernel of an Amazon Linux AMI:
Q. Can I perform an in-place upgrade from an existing version of Amazon Linux AMI to Amazon Linux 2?
No, an in-place upgrade from the existing Amazon Linux image to Amazon Linux 2 is not supported. We recommend that you test your application on a fresh installation of Amazon Linux 2 first before migrating.
On the other hand if you are running Amazon Linux 2 with kernel 4.14, this should very much be possible by installing and enabling through amazon-linux-extras and running the update using something like the following:
$ sudo amazon-linux-extras install kernel-5.10
Pure speculation for this last part but I believe it is generally recommended to migrate your workload to the latest AMI if at all possible but this should be sufficient otherwise.
