I have to connect to server through pptp vpn but there is no option in iPhone 7

PPTP is obsolete and is no longer considered secure.

Talk to your IT department.

They need to implement a VPN solution that is secure. PPTP is a massive security risk.

A VPN (virtual private network) provides secure access over the Internet to private networks, such as the network at your organization. You may need to install a VPN app from the App Store that configures your iPhone to access a network. Contact your system administrator for information about the app and settings you need.

iPhone never had PPTP (Point-to-Point Tunnelling Protocol) It always had IKEv2, IPsec & L2TP

Watch the GIF below made on iPhone 6 iOS 12.4.5

“We people” are users like you, we didn’t remove anything. But it’s likely that Apple removed it because pptp is so last millennium, is replete with serious security issues, and has been largely replaced by l2tpv3. No one who wants a secure tunnel protocol should use it. See:https://en.wikipedia.org/wiki/Point-to-Point_Tunneling_Protocol, especially the first paragraph.

The Point-to-Point Tunneling Protocol (PPTP) is an obsolete method for implementing virtual private networks. PPTP has many well known security issues.

If your office has a non-standard VPN you may need to install a profile to support it. Ask your IT department.

This is a user-to-user technical support site operated by Apple, you aren’t replying to Apple employees. Contact your IT department.