Why when i connect my external trackpad my macbook sees it as a mouse??

I have MacBook Pro M3Pro

last version Sonoma (14.7.1)

I also did a refund and tried a new trackpad, still the same…

I tried connecting it to my girlfriend's laptop(Macbook Pro M2) it also connects like a mouse…

Because of this I can only use it as a mouse, there is no trackpad functionality...

Please help 🙏🏻🙏🏻🙏🏻