Yii2 - how to upload to hosting?

Question

Yii

uploaded to hosting yii2. set up the base. this error comes out

PHP Fatal Error – yii\base\ErrorException
Call to undefined function yii\helpers\mb_strlen()

    1. in /home/laffkauz/public_html/vendor/yiisoft/yii2/helpers/BaseStringHelper.php at line 31
    22232425262728293031323334353637383940

                        {
        /**
         * Returns the number of bytes in the given string.
         * This method ensures the string is treated as a byte array by using `mb_strlen()`.
         * @param string $string the string being measured for length
         * @return int the number of bytes in the given string.
         */
        public static function byteLength($string)
        {
            return mb_strlen($string, '8bit');
        }
     
        /**
         * Returns the portion of string specified by the start and length parameters.
         * This method ensures the string is treated as a byte array by using `mb_substr()`.
         * @param string $string the input string. Must be one character or longer.
         * @param int $start the starting position
         * @param int $length the desired portion length. If not specified or `null`, there will be
         * no limit on length i.e. the output will be until the end of the string.
                    

    2. yii\base\ErrorHandler::handleFatalError()

Answer 1

Enable the module on mbstring hosting

Answer 2

What exactly is in the phrase
Are you not clear? How else to formulate, so that you would understand that the mb_strlen function is missing?
"An undeclared (non-existing) function 'function name' was called" - how else can this be interpreted?
And what stopped you from driving a mistake into Google and finding 2000000000 solutions ?