get text wrote in html paragraph using PHP

I've a paragraph contains some data which I want to insert these data into database, but when I try to insert these data into database PHP return an error this is my PHP code

if($conn->connect_error){
            die("Connection Failed ". mysqli_connect_error());
        } else{
            //connection successfull so do something ...
            $name = $_POST['seq_name'];
            $seq = $_POST['Seq'];
            $GC = $_POST['result1'];
            $Comp = $_POST['result2'];
            $Trans = $_POST['result3'];
            $Rev = $_POST['result4'];

            //GC button is clicked
            if($_POST['btn'] == 'functions'){
                $sql = "insert into functions (seq_name,sequence,GC,complement,rev_comp,transcript) values('$name','$seq','$GC','$Comp','$Rev','$Trans')";
                
                if($conn->query($sql) === TRUE) {
                    echo "<h3>Successfully inserted</h3>";
                    echo "<br>";
                    echo "GC Content is : ". $GC;
                    echo "<br>";
                    echo "Complement for entered sequence is : ". $Comp;
                    echo "<br>";
                    echo "Reverse Complement for entered sequence is : ". $Rev;
                    echo "<br>";
                    echo "Transcription is : ". $Trans;
                } else {
                    echo "<h3>Failed to insert</h3>";
                }
            }
}

and this is my HTML

<form action="action.php" target="_blank" mathod="POST">
   <p>GC</p>
   <p id="result1" name="result1"></p>
   <br>
   <p>Complement</p>
   <p id="result2" name="result2"></p>
   <br>
   <p>Transcripe</p>
   <p id="result3" name="result3"></p>
   <br>
   <p>Reverse Complement</p>
   <p id="result4" name="result4"></p>
</form>

so how can I read these paragraphs to insert its data into database

source https://stackoverflow.com/questions/67942296/get-text-wrote-in-html-paragraph-using-php