On 1 ip adress multiple dockers and domain names

hello,

i have a question.

i have a server with 1 ip adress
but i want to host 2 or 3 instances
of Odoo in it in a docker with also
3 different domain names.

is this possible, because al 3 instances
have the same ip adress only a different port.

and with dns i can only enter an ip adres without port number.

i hope someone can help me with this
because im completely new with this.

kind regards,

Jay