WEBHOOK_SECRET = 'webhook secret key';
post '/payload' do
    request.body.rewind
    body = request.body.read
    signature = request.env['HTTP_X_TAWK_SIGNATURE']
    unless verifySignature(body, signature))
        // verification failed
    end
    // verification success
end
def verifySignature(body, signature)
    digest = OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha1'), WEBHOOK_SECRET, body)
    return digest == signature
end