error was not declared in this scope when combime some string and send or print

   String webpage = "<h1>Hello</h1>&lth2>World!</h2><button>LED1</button>";
     String cipSend = "AT+CIPSEND=";
     cipSend += connectionId;
     cipSend += ",";
     cipSend +=webpage.length();
     cipSend +="\r\n";


for last line arduino IDE show this error:
‘cipsend’ was not declared in this scope

what should i do???

cipsend != cipSend

You Need to understand that the Arduino language is case sensitive. A variable defined with mixed case does not exist with all lower case.
Not all programming languages work that way, but most C based ones do.

capital S cipSend