Agile Cards Cloud Plugin can be installed directly from UPM in your JIRA Cloud instance ('Cog' Menu > Add-ons > Search the Marketplace field) or from plugin page on Atlassian Marketplace. You can choose free trial for one month to check if our plugin suits your needs. More detailed documentation about installing JIRA Cloud plugins can be found here: https://confluence.atlassian.com/display/AOD/Subscribing+to+JIRA+Add-ons. Please remember that, contrary to the JIRA Server plugins, in JIRA Cloud all plugins are sold in a form of monthly subscription.