Add new or edit existing posts & pages. Within the editor, find the + icon and click it. Search for Publitio. Once Publitio is selected, a block will appear where you will have the possibility to directly upload new images & videos to Publitio.
After clicking the "Select file from Publitio", a new window will open with all of your files currently stored on Publitio. Also, you can use it to upload new files from your device directly to Publitio.
Select the desired way of inserting the file onto your page/post.