Recliner hold down bracket help please.

We recently removed a love seat/"bed" from our 5er to switch to recliners. This is on a slide.
A friend was kind enough to donate his hold downs and hardware from the recliners he removed but his recliners were on the floor not on a slide.
The slide floor is not wood and appears to be metal or some type of composite. I am hesitant to drill into it to mount the brackets. Should I mount the brackets to the slide or go into the wall of the slide on one side and the back of the dinette on the other. Thanks for any input.