jeurissen Currently the sidePanel.close() method is not implemented. this has been added by Chrome. See implementation details: https://github.com/w3c/webextensions/pull/837 This API should close sidePanels. Version 1.1.1 (149), WebKit 625.1.8 Tahoe (26)
jeurissen Related issues: https://orionfeedback.org/d/14296-windowclose-is-a-no-op-in-extension-sidebars https://orionfeedback.org/d/14298-calling-sidebaractionclose-from-a-sidebar-gives-unable-to-find-toolbar-item-error
