DHCP POOL

Greetings

I have a question regarding DHCP, i have a pool of IPs
assigned to Wireless Devices (ubiquiti devices) this are in bridge mode, and those devices are
connected to a router.
The thing is that i get assigned 2 Ips from the pool, 1 for the ubiquiti and 1 for the router…
How can i reuse the ip assigned to the ubiquiti device to the router?

you can set a static IP on the device so that it does not request an IP.

You can not reuse an IP. Each device needs a unique address so that it can be managed.

so how isp share the ip that a modem has assigned
to our router?

They do not share. The modem is assigned a private IP that is used for management

so how i could do that?
create a new pool and ??

You would need to statically assign the devices to IP outside of the range.