Does the following link show your motherboard?
https://www.asus.com/us/Motherboards/ROG-Strix-X570-E-Gaming/overview/
There is only one physical LAN port which appears to support the following speeds:
10 Mbps, 100 Mbps, 1 Gbps, and 2.5 Gbps.
Reference:
https://kb.netgear.com/000060674/Wh...t-work-with-my-Nighthawk-Tri-Band-AX12-router
Your network must be able to support 2.5 Gbps in order for you to use 2.5 Gbps.
Here is a good summary (somewhat dated) about 2.5 Gbps
https://arstechnica.com/gadgets/2016/09/5gbps-ethernet-standard-details-8023bz/
You may find the following review (via Tom's Guide) interesting.
https://www.tomsguide.com/us/asus-rt-ac86u-router,review-6143.html
Depending on the overall configuration of your network 2.5 Gbps port is not likely going to be restrictive.