The best way to get support for free products is to create a thread on the wordpress.org forum for the matching plugin.
- Simple Links – https://wordpress.org/support/plugin/simple-links
- Advanced Sidebar Menu – https://wordpress.org/support/plugin/advanced-sidebar-menu
- Go Live Update URLS – https://wordpress.org/plugins/go-live-update-urls/
For premium plugins you may use the mentioned forums or submit a request using the contact form.