In case you would like to have PPTP VPN server but no such is installed. But first things first. For such an obsolete hardware and software keep in mind that accessing it requires passing old host key algorithms and cipers. Then:

components install vpnserver
components commit
# now it will reflash software and reboot
service vpn-server
no isolate-private
# here you apply regular PPTP configuration (see my other posts)
# ...
system configuration save
copy running-config startup-config

If you have other VPN types enabled, better disable it as you will be using PPTP and not SSTP or OpenVPN/WireGuard. Now, for HTTP access, most of the time it will be configured for local network access only. We can change this:

ip http security-level public
ip http port 81

Changing HTTP UI port to something different than default will give us ability to run other service on that port and do port forwarding to inside of local network.