{% set currentSite = craft.app.request.getQueryParam('site') %}
{% set siteId = craft.app.sites.allSiteIds()[0] %}

{% if currentSite != '' %} 
    {% set siteId = craft.app.sites.getSiteByHandle(currentSite).id %}
{% endif %}

{% redirect 'craftagram/settings/' ~ siteId ~ '?site=' ~ craft.app.request.getQueryParam('site') %}