Modified code...

gistfile1.txt

`use strict`;

const telegraf = require(`telegraf`);
const { Markup } = telegraf;
const bot = new telegraf(`secret`);
const botId = bot.token.split(`:`)[0];
var map = new Map();

bot.catch(console.log);

bot.context.keyboard = function () {
    const { id } = this.message.new_chat_member;
    return Markup.inlineKeyboard([//btn[Math.round(Math.random()*btn.length)]
        Markup.callbackButton(`${'I\'m not a bot 🤖'}`, `unmute.${id}`)
    ]).extra();
}

bot.command([`start`, `help`], async (ctx) => {
    if (ctx.chat.type === `private`) {
        await ctx.reply(
            `Hi, I can help you prevent spam attacks in your group. Just add me to your group with permission to ban and I will mute all new users until they prove their humanity. If you give also give me permission to delete messages, I can delete join messages after the user is unmuted.`,
            { parse_mode: `markdown` }
        );
    }
});

bot.on(`new_chat_members`, async (ctx) => {
    const { message_id } = ctx.message;
    const { first_name, id } = ctx.message.new_chat_member;
    const { title, id: chatId } = ctx.chat

    if (id == botId) {
        const { user, status } = await ctx.getChatMember(ctx.from.id);
        const statuses = [`creator`, `administrator`];

        if (!statuses.includes(status)) {
            await ctx.reply(
                `Hi [${user.first_name}](tg://user?id=${user.id}). Thanks for adding me but you don't seem to have admin rights here so I will have to leave - please ask an admin to add me back :)`,
                { parse_mode: `markdown` }
            );

            await ctx.leaveChat();
        }

        return;
    }

    try {
        await ctx.restrictChatMember(id, {
            can_send_messages: false
        });

        const reply = await ctx.reply(
            `Hi ${first_name}, for the safety of this chat, please also confirm your humanity by clicking the button below within 48 hours.`, // Can include ${title}
            {
                ...ctx.keyboard(),
                reply_to_message_id: message_id,
            }
        );
        const timeout = setTimeout(() => {
 			// delete reply or edit with "message expired. message an admin to be unmuted"
 			ctx.deleteMessage(reply.message_id);
 			bot.telegram.unbanChatMember(chatId, id);
		}, 10000);
	map.set(`${chatId}:${id}`, timeout);
    } catch (err) {
        switch (err.description) {
            case `Bad Request: can't demote chat creator`:
                ctx.reply(`Why would you leave if you're the creator?`);
                break;

            case `Bad Request: user is an administrator of the chat`:
                break;

            default:
                await ctx.reply(err.description);
                await ctx.leaveChat();
        }
    }
});

bot.action(/unmute\.(\d+)/, async (ctx) => {
    const clickedId = ctx.callbackQuery.from.id;
    const unmuteId = ctx.match[1];
    const chatId = ctx.callbackQuery.message.chat.id;

    if (clickedId == unmuteId) {
        try {
            await ctx.restrictChatMember(clickedId, {
                // until_date: ((Date.now() + 86400000) / 1000)*2, // 48 hours
                can_send_messages: true
            });
        } catch (err) {
            console.log(err);
        }

        ctx.deleteMessage();
        const key = `${chatId}:${clickedId}`;
		clearTimeout(map.get(key));
		map.delete(key);

        if (ctx.callbackQuery.message) {
            const { reply_to_message: reply } = ctx.callbackQuery.message;

            ctx.deleteMessage(reply.message_id)
                .catch(() => { /* Do nothing */ });
        }
    } else {
        ctx.answerCbQuery(`⛔ Sorry, this button doesn't belong to you! ⛔`);
    }
});

bot.startPolling();