Upgrade Fortinet APs (ex MERU) - Help

Hi everyone, I have a WiFi system managed by a controller "8.4-0build-7 | MC1550." Most of the access points (APs) are all aligned with the version "8.4-0build-7." The model of the APs is AP822e. They are quite old, but they work perfectly. However, a few of them are still running a very old version, "6.1-1-3," and I can’t use them as they are disabled at the operational level.

These are old devices, and I can no longer get commercial support for them. I’ve tried several distributors, but none of them can sell me commercial support for these devices.

I kindly ask if anyone can share the necessary updates to bring the APs from version "6.1-1-3" to version "8.4-0build-7." I imagine it will be necessary to first upgrade to version 7.

I’m desperate and don’t know what else to do. I’ve tried everything. Thank you in advance to anyone who can help me.