LTM Upgrade from 9.3.0 to 10.2.4

according to the release note:

Upgrading from version 9.3.x or 9.4.x

If you plan to install this version of the software onto a system running 9.3.x or 9.4.x, you must perform a one-time upgrade procedure to make your system ready for the new installation process. When you update from software version 9.3.x or 9.4.x to 10.x, you cannot use the Software Management screens in the Configuration utility. Instead, you must run the image2disk utility on the command line. For information about using the image2disk utility, see the BIG-IP Systems: Getting Started Guide.

Upgrading from versions earlier than 9.3.x

You cannot roll forward a configuration directly to this version from BIG-IP version 4.x or from BIG-IP versions 9.0.x through 9.2.x. You must be running software version 9.3.x, 9.4.x, 9.6.x, or 10.x. For details about upgrading to those versions, see the release notes for the associated release.

so you are good to go directly.