6700 xt is not being use

As I mentioned, the GPU is not just another bit of the CPU. They are entirely different devices, and use completely different mathematical and code formats. 

So their program documentation lists specifically what processes may use the GPU if avaliable, and if you don't have any of those effects or processes going, then there is no expectation of utilizing the GPU.

Plus even when the GPU will be used for something, it is used as the CPU is ready to send something to it. Which can be affected by quite a range of things even including cache read/write sustained speeds.

So with more information on your sequence media and effects , we could make educated guesses as to usage issues.

okay, so let's say premiere it's using my GPU. The thing is at the moment of exporting in task management it's just using my CPU at 100% and GPU is 20% sometimes 5%

They changed the behavior ... if it is grayed out, inside the program menus, that is now because it is being used and users can no longer disable the GPU inside the program.

In order to disable the GPU, to go to Software Only, you have to close Premiere, relaunch holding the Shift key down, and select Software Only.

Past that, it uses GPU resources for specific things, and not as just another helper to the CPU/general processing.

Since Premiere Pro 25.2, your 6700 XT is automatically selected as renderer. If that's the only GPU in your system, then you cannot change it at all–that is, you're permanently stuck with OpenCL GPU hardware rendering. And while 25.2 to 25.3 still have software rendering as an option only when you launch Premiere Pro in troubleshooting mode by holding down the Shift key at the same time you launch Premiere Pro, that option will disappear completely with the upcoming version 25.4.

In other words, you're stuck permanently with OpenCL GPU acceleration in Premiere Pro.

On a side note, if you have a GPU that's too old to be supported in Premiere Pro, or if you have a graphics driver that's too old, you will no longer be able to run Premiere Pro at all beginning with the aforementioned version 25.4 as software-only rendering will be completely removed from the program. (That is, Premiere Pro will still launch but will give you an error message with absolutely no choice whatsoever except to exit the program.)