Auto Handshake certificate ethernet

connected to server but no encryption data !! and i get this error ...

400 The plain HTTP request was sent to HTTPS port
HTTP/1.1 400 Bad Request
** Connection Failed **
receiving from remote server
Print Data Available

Server: nginx/1.14.2
Date: Sun, 22 Aug 2021 15:08:46 GMT
Content-Type: text/html
Content-Length: 271
Connection: close

<html>
<head><title>400 The plain HTTP request was sent to HTTPS port</title></head>
<body bgcolor="white">
<center><h1>400 Bad Request</h1></center>
<center>The plain HTTP request was sent to HTTPS port</center>
<hr><center>nginx/1.14.2</center>
</body>
</html>

this library sends data in plain text mode & doesnt encrypt data
thats why nginx gives error 400 bad request