How I can Configure this Topology with the red line route, In My PC I want to access the web App ( with IP Private ) and I also can surfing the internet.
Is my PC must be configure with 2 Gateway. or i must be setting the route list im My Mikrotik
You’ll likely also have to set a NAT rule to src-nat (or masquerade) for traffic out that interface as well, so it will appear as coming from 10.10.10.162 (as their network likely does not have a route back to you for 192.168.88.0/24)
yep so .161 doesnt know how to get back to you, which likely means you are presenting as your internal IP 192.168.88.x. Like a normal internet connection, you’ll need to NAT your connection out of that interface.
I’ve steered you to the likely answer - give it a go and tell me if it works. If you are not understanding what I am explaining then perhaps this task is beyond your capabilities and you should hire someone to help you. My explanation explains why you would not be able to ping the web server from your PC (until you add the NAT rule).