How can I solve my problem posting number sign to make a hashtag?

I’m trying to post # sing to make some words turn to hashtags but the code doesn’t work and it’s via API using this code:

true == function()
{
var getMyItem = function (str)
{
if (sessionStorage.getItem(str) == null)
{
setMyItem(str, 0);
return 0;
}
return sessionStorage.getItem(str);
}
var setMyItem = function (key, value)
{
sessionStorage.setItem(key, value);
}

function bot(post)
{
const Http = new XMLHttpRequest();
var Token="xxxxxxxxxxxxxxxxxxxxxxxxxxxxx"; // Token
var ID= "xxxxxx";
var url= 'https://bot.xxx/api/'+Token+'/sendMessage?text='+post+'&chat_id='+ID;
Http.open("GET", url);
Http.send();
}
// you need to change the url variable contents for your own Telegram API or those of the same SN APIs..

So when it comes to call the post like with this code:

var myDate = new Date().toTimeString().replace(/.*(d{2}:d{2}:d{2}).*/, "$1");
var post_n = "%23Hi. It's: " + myDate + "n";
var post = encodeURI(post_n);

if (getMyItem(key + "htr") != "yes")
{
bot(post);
setMyItem((key + "htr"),"yes");
}


return true;
}
}()

, it doesnt support # sign in my browsers including Chrome an Firefox and nothing is sent actually.
So if it were for Telegram, the bot would look like this (and I donno if it works or not but I’m talking about another SN):
var url= ‘https://api.telegram.org/’+Token+’…

Please tell me how to send # code. By the way, “%23” doesn’t work.