Hi,
What is the full model number of the laptop as shown on the product info label on the bottom of the laptop?
Knowing this will help to find the correct part if there's a broken hinge, clip etc under the spacebar.
Here's a [https://www.youtube.com/watch?v=R1GgbKRxvLk|video] that gives some idea as to how they're assembled. The clips and hinges on your model may be different so that's why knowing the exact model number will help.
Search online for ''HP (insert full model number) replacement keys'' to find suppliers that suit you best.
Here's a [https://www.replacementlaptopkeys.com/hp-pavilion-15-laptop-key-replacement/|supplier] just to give an example. ''Take note of what is said in the Description.'' They also have installation videos as well.