Hold up, your Mikrotik router is behind a cable modem that is giving out 192.168.100.0/24 addresses, so your ether1 interface is in this range?
Have you set up port forwarding on your cable modem? If not, that's where you need to start. Whichever device gets the public IP is where you need to do the initial port forward. Then you have a choice - either set the port forward on the modem directly to 10.10.10.191 if you have dynamic or static routing enabled, or set up a second port forward on the Mikrotik. The second option means your port forward on the modem needs to point to the Mikrotik ether1 IP address, so it will need to be static (not DHCP).
Your dstnat rule still needs work. Under the General tab, you only need to specify the chain (dstnat), protocol (TCP) and dst. port (88). Remove everything else, as this tab is where you set up what traffic to match.Leave the action tab as you have it.
/ip firewall nat
add chain=dstnat protocol=tcp dst-port=88 action=dst-nat to-addresses=10.10.10.191 to-ports=88 log=yes log-prefix=cam-frnt
You will then have two port forwards:
on cable modem: public-IP:88 -> MT-ether1-IP:88
on Mikrotik: MT-ether1-IP:88 -> 10.10.10.191:88