How to send a UDP packet through a wireguard VPN tunnel? Packets are not encrypted

Question

I'm using a socket program (in C) to send a UDP packet from a wireguard client to the server. I use the socket sendto() method to send the packet. At the server end I capture the packet using another server program (in C & pcap).    As I need to send the packet through the wireguard VPN tunnel,  In my client socket program, I have used the wireguard VPN tunnel IP address and ports as the ip address and port for the socket program as follows.

Server IP - 10. 6. 0. 1
Server port - 51820 

My server and the client configuration details are as follows:

Client end wg0.conf file

[Interface]
PrivateKey = <client’s private key>
Address = 10.6.0.2/24

PostUp = ip rule add table 200 from 192.168.30.211
PostUp = ip route add table 200 default via 192.168.30.1
PreDown = ip rule delete table 200 from 192.168.30.211
PreDown = ip route delete table 200 default via 192.168.30.1

[Peer]
PublicKey =  servers’s public key
AllowedIPs = 10.6.0.1/24
Endpoint = 192.168.30.209:51820

Server wg0.conf

[Interface]
PrivateKey = <server’s private key>
Address = 10.6.0.1/24
ListenPort = 51820
SaveConfig = true
PostUp = ufw route allow in on wg0 out on ens192
PostUp = iptables -t nat -I POSTROUTING -o ens192 -j MASQUERADE
PreDown = ufw route delete allow in on wg0 out on ens192
PreDown = iptables -t nat -D POSTROUTING -o ens192 -j MASQUERADE

[Peer]
PublicKey = clients’s private key
AllowedIPs = 10.6.0.2/24

When I’m sending the packets from the client, by using wireshark I listen to the wireguard wg0 interface. I can see the packets are  moving through the wg0 tunnel on the client side and on the server, I receive the packets. However, the main problem is, I think these packets are not encrypted (raw data is displayed). In both client and server captured packets in wireshark, I can read the data portion of the packet.  Also the protocol is displayed as UDP (not wireguard).

Even though my packets are sent through the tunnel, they are not encrypted. What is the reason for this? 

Is there any fireguard library that can be used to send packets? I tried to use this single file C library https://git.zx2c4.com/wireguard-tools/tree/contrib/embeddable-wg-library , but the wireguard.h is not providing any methods to send packets. Any possible solutions?