use two additional monitors with "HP 27 Pavilion All-in-One PC, 10th Gen Intel i7-10700T Processor,

[idahoblaster]

I want to use two additional monitors with my "HP 27 Pavilion All-in-One PC, 10th Gen Intel i7-10700T Processor, 16 GB RAM, Dual Storage 512 GB SSD and 1TB HDD, Full HD IPS 27 Inch Touchscreen, Windows 10 Home, Keyboard and Mouse (27-d0072, 2020)".    I can only get one to work.

[banhien]

@idahoblaster 

What exactly is your machine ? Please use the following way to find out the model/product of your machine

                          https://support.hp.com/us-en/document/bph07555

For security reason, please do NOT post its Serial number (s/n) on Internet.

Regards.

[itsmyname]

@idahoblaster -- doing a Google-search for "HP 27 Pavilion All-in-One PC, 10th Gen Intel i7-10700T", I found a web-page that lists: HP 27 Pavilion All-in-One PC, 10th Gen Intel i7-10700T Processor, 16 GB RAM, Dual Storage 512 GB SSD...

The important part is the model-number:  27-d0072

That lead me to a page that describes your computer: HP Pavilion All-in-One - 27-d0072 Product Specifications | HP® Customer Support

that includes a link to your computer's motherboard: HP Desktop PCs - Motherboard Specifications, Brighton | HP® Customer Support

that lists:

Back I/O ports:

(1) HP 3-in-1 memory card reader (supports Secure Digital (SD, SDHC, and SDXC))
(1) USB 3.2 Gen 1 Type-C (5 Gbps data rate)
(3) USB 3.2 Gen 1 Type-A (5 Gbps data rate)
(1) HDMI 1.4/ HDCP 2.2 output port
(1) HDMI 2.0 (UHD); HDMI 1.4 (QHD, FHD)/ HDCP 2.2 (UHD); HDCP 1.4 (QHD, FHD) input port
(1) Power input port
(1) RJ-45/Ethernet port

Side I/O ports:

(1) Headphone/microphone combo jack
(1) USB 3.2 Gen 1 Type-A (supports Battery Charging 1.2)

So, my "short" answer has three parts:

1. your computer can receive HDMI-input, and display the output from any HDMI-output device (DVD/BluRay player, or Cable/Satellite TV box);
2. your All-In-One computer has just one HDMI-output port, to support just one external monitor;
3. I see: one USB 3.2 Gen 1 Type-C and two USB 3.2 Gen 1 Type-A. This implies that it might be possible to connect a monitor to one of these ports, with an appropriate cable.

I hope this helps.