KVM Switch Setup Help

My mother has started working from home more, and my neice is at the age where she is starting to have more homework.

They have 3 computers, the older family tower, mom's work laptop, nieces laptop. Theyre constantly unhooking printers, a cricuit, and other peripherals.

I decided to suprise them with a triple monitor setup and KVM switch to clean up the home office for Christmas and condense everything. I basically mimicked my setup at home. I have however run into two snags with their setup.

I will be asking questions about this KVM Switch:

https://www.amazon.com/HDMI2-1-Displayport-Monitors-Computers-Switches/dp/B0FLT5QTFK?pd_rd_w=DeGbu&content-id=amzn1.sym.d835d594-8c58-45a9-b057-50d11603f9e9&pf_rd_p=d835d594-8c58-45a9-b057-50d11603f9e9&pf_rd_r=5HCSAXNBCGJ3TT66A201&pd_rd_wg=T00IX&pd_rd_r=00d9a23a-e5c9-4f30-876c-e986fdfdf99a&pd_rd_i=B0FLT5QTFK&psc=1&ref_=pd_basp_m_rpt_ba_s_1_nped_sc

I will be asking questions about this dock:

https://www.amazon.com/DisplayPort-Docking-LIONWEI-Ethernet-Thunderbolt/dp/B0BK8QNY2W?pd_rd_w=HGaj8&content-id=amzn1.sym.d835d594-8c58-45a9-b057-50d11603f9e9&pf_rd_p=d835d594-8c58-45a9-b057-50d11603f9e9&pf_rd_r=1VHZCX644BKJGR8KCYY3&pd_rd_wg=zu4PH&pd_rd_r=19829ce3-86ac-4299-be81-6f6b8ea63653&pd_rd_i=B0BK8QNY2W&psc=1&ref_=pd_basp_m_rpt_ba_s_1_sc

Snag 1: The older tower has two HDMI ports, no hope here of running 3 monitors. The issue is the KVM switch I have accepts 2 displayport inputs and one HDMI. Basically I need to get my HDMI signal from the computer into a display port hole in the KVM switch. This for some reason is really confusing me. Should I put a HDMI to DP dongle at the computer and run a DP cable to the KVM? Does that dongle need to be powered? Alternatively, do I run an HDMI cable close to the KVM switch and run an HDMI to DP dongle there? Would it need powered?

Snag 2: The two laptops do not charge with the dock I bought.

I have been unable to find a dock that does what I need though that will charge. They are USB-n thunderbolt.

The main issue is I can't seem to locate a KVM switch that has 2 display port and 1 HDMI and is also powered to charge the laptop. I find them instead with two HDMI and one display port.

Any help or recommendation on products is greatly appreciated to finish this early Christmas present-