I can't get if notification exists

Greetings. Thanks in advanced for your help.

I am trying to make a request to the CRM API to find out if a notification exists by passing a channel ID as a parameter. All requests end with Bad Request.

Here is my request

https://www.zohoapis.com/crm/3/actions/watch?channel_id=10000000810244

I receive something like this

 <div class="crmErrorPgCont crmErrorHeight" data-zcqa="crm_error_page"
        data-errormessage="Sorry the page you have requested was not found">
        <div class="crmErrorPgBody">
            <div class="crmErrorPgImgContr">
                <!-- <span class="crmErrorPgImg"></span> -->
                <img class="crmErrorPgImg" data-image-mode='true' src='https://static.zohocdn.com/crm/images/crm-iam-errorPage_lightmode_2eb563c9ea6d989a69e2be6276245761_.png'/>
            </div>
            <div class="crmErrorInfoSection">
                <p class="crmErrorPgErrText1">Invalid URL</p>
                <p class="crmErrorPgErrText2">Unable to process your request as the URL
                    <span class='crmErrorUrl'>&#x2f;crm&#x2f;3&#x2f;actions&#x2f;watch</span> is invalid.</p>
                <!-- No I18N -->
                <a class="crmErrorPgHomeLink" href="/crm/ShowHomePage.do">
                    <button data-zcqa="home_errorPage" class = "primarybtn" >Go to Home page</button>
                </a>
            </div>
        </div>

Awaiting your kind help