I am sending text message having Japanese characters.
Here is my message
In japanese
このOTPを使用してQuikドライブにログインします。 このOTPを誰とも共有しないでください
You need to use Unicode to send non GSM characters via SMS and then also set the unicode parameter.
Here is a PHP example:
$converted = iconv(
"UTF-8",
"UCS-2BE",
"このOTPを使用してQuikドライブにログインします。 このOTPを誰とも共有しないでください"
);
$sms_data = urlencode(bin2hex($converted));
http://api.clickatell.com/....text=$sms_data&unicode=1
NOTE: Unicode messages are generally shorter than non-unicode messages, so be careful as you may pay for more than one message, detailed info over here:
https://archive.clickatell.com/developers/api-docs/concatenation-advanced-message-send/
Snippet:
70 (16-bit) characters allowed in a single SMS message part 67 (16-bit) characters used per message part when sending concatenated messages
You probably need to set the charset to UTF-8 before sending. I don't know what the actual charset your'e using in your code but make sure its UTF-8.
If you already using UTF-8, make sure the actual Font you using is able to handle the Japanese letters.
For more explanation on how to handle Japanese letters, maybe you should check this:
https://www.kanjidatabase.com/japanese_developer_tips.php