Question about Logitech MK470 Combo

Hello, My attempts to connect the two devices together to a Logitech Unifying receiver have unfortunately all failed.
Whether there is a "trick" for this, you might have to ask Logitech yourself via support. However, as far as I have searched the net for corresponding statements, the result has unfortunately also been correspondingly negative.
I am once again disappointed with Logitech for what they have done here in terms of sustainability. It is an expensive "throwaway product" that is also "addressed" to the younger generation in the advertising.
Irresponsible in my opinion.
Here is the search result directly from the manufacturer for a possible replacement part:
https://support.logi.com/hc...
There are no more spare parts for this product.