My network has the fallowung conpenent:

Hotspot+PPPoE Mikrotik router (intel PC)
Lan 192.168.2.1
WAN 192.168.1.1

RB450 router used to combine 3 lines
lan 192.168.1.50
wan1 192.168.3.1
wan2 192.168.7.1
wan3 192.168.9.1
Server 10.10.10.1 ( the server connected to this port and has ip 10.10.10.10)

Intel pc lan post is connected to the lan port of RB450.

I added i ip--<DNS --> static DNS in the Intel PC
http://www.****.com ----> 10.10.10.10

hotspot user can access the site in the server using the url http://www.***.com but PPPoE user can only access the site using 10.10.10.10. how can I let the PPPoE user access using url too?

You'll need to add a rule that forces the PPPoE user to use the Mikrotik's DNS server or add it in the PPPoE configuration so they are assigned those DNS servers when they connect.

Otherwise they'll just lookup any external server which won't know about your custom DNS entry on the local Mikrotik.

It would be better to set a redirect rule in your nat to redirect all DNS request from either the pppoe users or all users to the router. This way even if users set their own DNS it will still be redirected to your router for DNS requests. Be sure to enable "allow remote requests".

Both ways would work but this way keeps the user from changing their own DNS and breaking what you are trying to achieve.

how to do this?

Same as any other redirect.

it worked . thank you