Check is the file manager loaded and ready to use
Flmngr.isFlmngrLoaded
(): boolean
Returns true if the Flmngr library is fully loaded and you can call the file browser. false is returned when Flmngr is not fully loaded, but some of the utility methods are still ready for use (i. e., this one).
Use this method only if you have an integration listed in the left column of the integrations table. If your integration is listed in the right column, just check if the window.flmngr variable is set.
When you call Flmngr methods like Flmngr.open({params}), Flmngr.upload({params}), and others, they will wait until Flmngr is fully loaded and then call the requested action automatically. Always check if Flmngr is loaded before calling such methods if you wish to execute the methods only when everything is ready.