Hi @oscowordpress1,
Thank you for reaching out to us for assistance. To clear all the Instagram account data, in the latest version of the plugin you can go to WordPress Dashboard > Instagram Feed > Customize, and at the bottom of the page click the Delete all Platform Data button.
This will not reset all customization options in the plugin, unfortunately. The only way to do this safely is to go to the Configure tab, ensure the Preserve settings when the plugin is removed setting is off, then deactivate and remove the plugin, and install again.
Please let me know if I can answer any other questions or concerns.
Best regards,
Louis