var icreateBaseUrl = 'https://icreate.domain.tld'
// And afterwards
redirectUrl = icreateBaseUrl + 'some/other/path/page.srv?pageId=123',

<script type="text/javascript">
if (typeof String.prototype.endsWith !== 'function') {
    String.prototype.endsWith = function(suffix) {
        return this.indexOf(suffix, this.length - suffix.length) !== -1;
    };
}
$(document).ready(function() {
    var redirectUrl;
    if (location.href.indexOf('/edit_') > -1) {
        redirectUrl = location.href.replace('/edit_', '/');
    } else {
        var icreateBaseUrl = 'https://icreate2.stage.domain.tld/';
        if (!icreateBaseUrl.endsWith('/')) {
            icreateBaseUrl += '/';
        }
        redirectUrl = icreateBaseUrl + 'icreate/modules/pageeditor3/page.srv?pageId=64158';
    }
    $(document).icrtShortcut({
        shortcutKey: 'f9_f9',
        redirectUrl: redirectUrl
    });
});
</script>

"#{base_url}/#{redirect_url}"

http(s)://icreate.domain.tld/some/other/path/page.srv?pageId=#{id}