Automatically open a FileChooser upon Plugin start

I am working on a Plugin, that crucially depends on importing a config.json to set up some parameters and objects etc.

I already have a working FileChooser with button and everything. First thing for me to do everytime I open the Plugin is clicking that Button and choosing the json file. So I thought it would be reasonable to just force-open the file chooser window every time the Plugin is initiated (NOT every time the GUI gets closed and re-opened again). I do not know how to do that, though.

I assume that there is something to be done in the PluginEditor’s constructor, somewhere near the addAndMakeVisible(chooser) part of the button, but I could not find anything that helped me in the documentation for TextButton.

tb_loadJSON.reset (new juce::TextButton ("new button"));
addAndMakeVisible (tb_loadJSON.get());
tb_loadJSON->setButtonText (TRANS("Import"));
tb_loadJSON->addListener (this);

Has anyone here ever had a similar situation, where an overlay window, e.g. a modal, was to be opened on top of the Plugin main view on startup?