Where is the write protect screw on this model? (photo included)

MrChromebox.tech has this to say about write protection schemes on HP laptops.

==== HW WP Implementation ====

• Early Chromebook models (2012-2013): use a jumper or switch to implement hardware write protection. All models prior to the 2013 Chromebook Pixel fall into this group.
• Pre-CR50 models (2014-2017): use a screw to complete the ground; removing it leaves the !WP pin floating, effectively disabled. The 2013 Chromebook Pixel was the first device to use a WP screw; all Haswell, Broadwell, Baytrail, Skylake, and Braswell-based devices do as well.
• CR50 models (2017+): On all Chromebook models with the CR50/Google Security Chip (all Kabylake/Apollolake and newer models), the !WP pin is controlled by the CR50.

On most early CR50 platforms, the CR50 sets the WP state to follow the battery sense line, so disconnecting the battery cable from the mainboard will disable the hardware write protect.

On some newer platforms, WP cannot be disabled by disconnecting the battery; instead there is an unpopulated jumper on the board which must be bridged.

It looks to me like your laptop falls under the category of a 2020 model, meaning it does not have a WP screw. You can read more about it on the MrChromebox website.