wireless router using another name

I need 2.4ghz for a device, my router only 5ghz name (A)
can I use another router connect via wireless and use another name (B)? so I can connect the 2.4 ghz device to 2.4

What router model is it?

A lot of models now use smart connect and will assign the same SSID to both bands.

In that case you need to turn off smart connect then you can assign a separate SSID to each band.

I have a EERO 7 that is 5ghz its suppose to know when 2.4 is needed
the other router will be older linksys ea7300
trying to get camera setup

Why do you want to use 2 routers? Doesn't each one have 2.4 and 5 GHz?

My router supports WiFi 6E. By default it has one SSID. When that is selected the computer selects which band is used. I changed that so each band has its own SSID name. That allows me to manually select which band to connect to in the WiFi settings.